<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019f8a30-84f3-7f3f-9c25-2334f2b0fe92,g:8a39a1bd-5535-45a7-bd6c-71324149b01a-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/CondensedConsolidatedStatementsofEarningsandComprehensiveIncomeUnaudited" xlink:type="simple" xlink:href="noc-20260930.xsd#CondensedConsolidatedStatementsofEarningsandComprehensiveIncomeUnaudited"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/CondensedConsolidatedStatementsofEarningsandComprehensiveIncomeUnaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019f8a30-862f-70bb-8d74-a0d063bdcd5c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019f8a30-862f-7ef2-9aa7-54f0075711be" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019f8a30-862f-70bb-8d74-a0d063bdcd5c" xlink:to="loc_us-gaap_StatementTable_019f8a30-862f-7ef2-9aa7-54f0075711be" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019f8a30-862f-73d8-95a4-91f6f143a2e2" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019f8a30-862f-7ef2-9aa7-54f0075711be" xlink:to="loc_srt_ProductOrServiceAxis_019f8a30-862f-73d8-95a4-91f6f143a2e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f8a30-862f-73d8-95a4-91f6f143a2e2_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019f8a30-862f-73d8-95a4-91f6f143a2e2" xlink:to="loc_srt_ProductsAndServicesDomain_019f8a30-862f-73d8-95a4-91f6f143a2e2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f8a30-862f-7ef5-9c27-8393c5d1555e" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019f8a30-862f-73d8-95a4-91f6f143a2e2" xlink:to="loc_srt_ProductsAndServicesDomain_019f8a30-862f-7ef5-9c27-8393c5d1555e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductMember_019f8a30-862f-72c5-a9fe-d92cea0d6622" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProductMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8a30-862f-7ef5-9c27-8393c5d1555e" xlink:to="loc_us-gaap_ProductMember_019f8a30-862f-72c5-a9fe-d92cea0d6622" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_019f8a30-862f-7d6d-8b47-6eddf99289b7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8a30-862f-7ef5-9c27-8393c5d1555e" xlink:to="loc_us-gaap_ServiceMember_019f8a30-862f-7d6d-8b47-6eddf99289b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019f8a30-862f-72bc-a07a-31aa8847f29c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f8a30-862f-70bb-8d74-a0d063bdcd5c" xlink:to="loc_us-gaap_Revenues_019f8a30-862f-72bc-a07a-31aa8847f29c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_019f8a30-862f-7962-b6ec-082ac9c25662" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f8a30-862f-70bb-8d74-a0d063bdcd5c" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_019f8a30-862f-7962-b6ec-082ac9c25662" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/CondensedConsolidatedStatementsofChangesinShareholdersEquityUnaudited" xlink:type="simple" xlink:href="noc-20260930.xsd#CondensedConsolidatedStatementsofChangesinShareholdersEquityUnaudited"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/CondensedConsolidatedStatementsofChangesinShareholdersEquityUnaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019f8a30-862f-74aa-88a4-37271da34572" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019f8a30-862f-7b65-bc71-1fa638b70257" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019f8a30-862f-74aa-88a4-37271da34572" xlink:to="loc_us-gaap_StatementTable_019f8a30-862f-7b65-bc71-1fa638b70257" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019f8a30-862f-7084-b7b4-f1c7bdf59714" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019f8a30-862f-7b65-bc71-1fa638b70257" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019f8a30-862f-7084-b7b4-f1c7bdf59714" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019f8a30-862f-7084-b7b4-f1c7bdf59714_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019f8a30-862f-7084-b7b4-f1c7bdf59714" xlink:to="loc_us-gaap_EquityComponentDomain_019f8a30-862f-7084-b7b4-f1c7bdf59714_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019f8a30-862f-7e7b-b608-0f16a66cd9f7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019f8a30-862f-7084-b7b4-f1c7bdf59714" xlink:to="loc_us-gaap_EquityComponentDomain_019f8a30-862f-7e7b-b608-0f16a66cd9f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019f8a30-862f-77a1-b1f1-7db05246173f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019f8a30-862f-7e7b-b608-0f16a66cd9f7" xlink:to="loc_us-gaap_CommonStockMember_019f8a30-862f-77a1-b1f1-7db05246173f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019f8a30-862f-7500-9af3-f76b99170c57" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019f8a30-862f-7e7b-b608-0f16a66cd9f7" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019f8a30-862f-7500-9af3-f76b99170c57" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019f8a30-862f-7c58-8f3b-567fb3b87746" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019f8a30-862f-7e7b-b608-0f16a66cd9f7" xlink:to="loc_us-gaap_RetainedEarningsMember_019f8a30-862f-7c58-8f3b-567fb3b87746" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f8a30-862f-7466-ae45-0868aee70f92" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019f8a30-862f-7e7b-b608-0f16a66cd9f7" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f8a30-862f-7466-ae45-0868aee70f92" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8a30-862f-7f35-af7f-33ea10808468" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f8a30-862f-74aa-88a4-37271da34572" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8a30-862f-7f35-af7f-33ea10808468" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019f8a30-862f-7239-99c6-d6ff14990b44" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8a30-862f-7f35-af7f-33ea10808468" xlink:to="loc_us-gaap_StockholdersEquity_019f8a30-862f-7239-99c6-d6ff14990b44" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_019f8a30-862f-7c4f-b7db-766eda8699fa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8a30-862f-7f35-af7f-33ea10808468" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_019f8a30-862f-7c4f-b7db-766eda8699fa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019f8a30-862f-752d-9c86-b11a1e8f8cb3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8a30-862f-7f35-af7f-33ea10808468" xlink:to="loc_us-gaap_NetIncomeLoss_019f8a30-862f-752d-9c86-b11a1e8f8cb3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStock_019f8a30-862f-7a1a-b631-abd4c483f1a6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8a30-862f-7f35-af7f-33ea10808468" xlink:to="loc_us-gaap_DividendsCommonStock_019f8a30-862f-7a1a-b631-abd4c483f1a6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_019f8a30-862f-7a4b-aee1-601f331a79b0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8a30-862f-7f35-af7f-33ea10808468" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_019f8a30-862f-7a4b-aee1-601f331a79b0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019f8a30-862f-7500-8ef7-d194bde89cbe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8a30-862f-7f35-af7f-33ea10808468" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019f8a30-862f-7500-8ef7-d194bde89cbe" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019f8a30-862f-7cd2-8613-fa504579ff3d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_019f8a30-862f-7f11-a3b7-87e43d914f72" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockDividendsPerShareDeclared"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019f8a30-862f-7f35-af7f-33ea10808468" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_019f8a30-862f-7f11-a3b7-87e43d914f72" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/CommitmentsandContingenciesUnauditedTables" xlink:type="simple" xlink:href="noc-20260930.xsd#CommitmentsandContingenciesUnauditedTables"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/CommitmentsandContingenciesUnauditedTables" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_noc_EnvironmentalRemediationRangeofFutureCostsLineItems_019f8a30-86d1-71cf-8ea0-9067d381623e" xlink:href="noc-20260930.xsd#noc_EnvironmentalRemediationRangeofFutureCostsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_EnvironmentalRemediationRangeofFutureCostsTable_019f8a30-86d1-79ef-8862-e3f26e2d3181" xlink:href="noc-20260930.xsd#noc_EnvironmentalRemediationRangeofFutureCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_noc_EnvironmentalRemediationRangeofFutureCostsLineItems_019f8a30-86d1-71cf-8ea0-9067d381623e" xlink:to="loc_noc_EnvironmentalRemediationRangeofFutureCostsTable_019f8a30-86d1-79ef-8862-e3f26e2d3181" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019f8a30-86d1-77a7-b059-ed8603ae9cda" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_noc_EnvironmentalRemediationRangeofFutureCostsTable_019f8a30-86d1-79ef-8862-e3f26e2d3181" xlink:to="loc_srt_RangeAxis_019f8a30-86d1-77a7-b059-ed8603ae9cda" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f8a30-86d1-77a7-b059-ed8603ae9cda_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019f8a30-86d1-77a7-b059-ed8603ae9cda" xlink:to="loc_srt_RangeMember_019f8a30-86d1-77a7-b059-ed8603ae9cda_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f8a30-86d1-7a0e-9922-046b1d0d0d88" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019f8a30-86d1-77a7-b059-ed8603ae9cda" xlink:to="loc_srt_RangeMember_019f8a30-86d1-7a0e-9922-046b1d0d0d88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_EnvironmentalRemediationTableTextBlock_019f8a30-86d1-714f-aef3-d429ace12e1a" xlink:href="noc-20260930.xsd#noc_EnvironmentalRemediationTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_noc_EnvironmentalRemediationRangeofFutureCostsLineItems_019f8a30-86d1-71cf-8ea0-9067d381623e" xlink:to="loc_noc_EnvironmentalRemediationTableTextBlock_019f8a30-86d1-714f-aef3-d429ace12e1a" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/SummaryofSignificantAccountingPoliciesUnauditedContractEstimatesDetails2" xlink:type="simple" xlink:href="noc-20260930.xsd#SummaryofSignificantAccountingPoliciesUnauditedContractEstimatesDetails2"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/SummaryofSignificantAccountingPoliciesUnauditedContractEstimatesDetails2" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInAccountingEstimateLineItems_019f8a30-862f-73c3-8128-e3c2c653f9db" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ChangeInAccountingEstimateLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfChangeInAccountingEstimateTable_019f8a30-862f-78df-ad5d-8790b018eaf6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfChangeInAccountingEstimateTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ChangeInAccountingEstimateLineItems_019f8a30-862f-73c3-8128-e3c2c653f9db" xlink:to="loc_us-gaap_ScheduleOfChangeInAccountingEstimateTable_019f8a30-862f-78df-ad5d-8790b018eaf6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019f8a30-862f-7edd-9118-2aa2d6d0f548" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfChangeInAccountingEstimateTable_019f8a30-862f-78df-ad5d-8790b018eaf6" xlink:to="loc_srt_ProductOrServiceAxis_019f8a30-862f-7edd-9118-2aa2d6d0f548" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f8a30-862f-7edd-9118-2aa2d6d0f548_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019f8a30-862f-7edd-9118-2aa2d6d0f548" xlink:to="loc_srt_ProductsAndServicesDomain_019f8a30-862f-7edd-9118-2aa2d6d0f548_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f8a30-862f-7614-b956-2d3a8d918b39" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019f8a30-862f-7edd-9118-2aa2d6d0f548" xlink:to="loc_srt_ProductsAndServicesDomain_019f8a30-862f-7614-b956-2d3a8d918b39" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_B21ProgramLRIPOptions15Member_019f8a30-862f-749d-8870-7711efb4a908" xlink:href="noc-20260930.xsd#noc_B21ProgramLRIPOptions15Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8a30-862f-7614-b956-2d3a8d918b39" xlink:to="loc_noc_B21ProgramLRIPOptions15Member_019f8a30-862f-749d-8870-7711efb4a908" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_B21ProgramLRIPOptions14Member_019f8a30-862f-7387-a44d-734fc42d286c" xlink:href="noc-20260930.xsd#noc_B21ProgramLRIPOptions14Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8a30-862f-7614-b956-2d3a8d918b39" xlink:to="loc_noc_B21ProgramLRIPOptions14Member_019f8a30-862f-7387-a44d-734fc42d286c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_B21ProgramLRIPOptions12Member_019f8a30-862f-70ed-924e-ea03c39ad3da" xlink:href="noc-20260930.xsd#noc_B21ProgramLRIPOptions12Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8a30-862f-7614-b956-2d3a8d918b39" xlink:to="loc_noc_B21ProgramLRIPOptions12Member_019f8a30-862f-70ed-924e-ea03c39ad3da" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_B21ProgramLRIPOptions35Member_019f8a30-862f-7241-89ba-0678272c0471" xlink:href="noc-20260930.xsd#noc_B21ProgramLRIPOptions35Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8a30-862f-7614-b956-2d3a8d918b39" xlink:to="loc_noc_B21ProgramLRIPOptions35Member_019f8a30-862f-7241-89ba-0678272c0471" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_SentinelEMDPhaseMember_019f8a30-862f-75c2-b325-2c6e1b88818f" xlink:href="noc-20260930.xsd#noc_SentinelEMDPhaseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8a30-862f-7614-b956-2d3a8d918b39" xlink:to="loc_noc_SentinelEMDPhaseMember_019f8a30-862f-75c2-b325-2c6e1b88818f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_HALOProgramMember_019f8a30-862f-77b1-9e18-70de4d8fadce" xlink:href="noc-20260930.xsd#noc_HALOProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8a30-862f-7614-b956-2d3a8d918b39" xlink:to="loc_noc_HALOProgramMember_019f8a30-862f-77b1-9e18-70de4d8fadce" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_RestrictedMicroelectronicsPortfolioMember_019f8a30-862f-7b11-8c98-f5dd11b330ad" xlink:href="noc-20260930.xsd#noc_RestrictedMicroelectronicsPortfolioMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8a30-862f-7614-b956-2d3a8d918b39" xlink:to="loc_noc_RestrictedMicroelectronicsPortfolioMember_019f8a30-862f-7b11-8c98-f5dd11b330ad" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_StandInAttackWeaponProgramMember_019f8a30-862f-7326-9e46-54018e7f3763" xlink:href="noc-20260930.xsd#noc_StandInAttackWeaponProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8a30-862f-7614-b956-2d3a8d918b39" xlink:to="loc_noc_StandInAttackWeaponProgramMember_019f8a30-862f-7326-9e46-54018e7f3763" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_GEM63XLProgramMember_019f8a30-862f-71a9-bd5a-07ef89566725" xlink:href="noc-20260930.xsd#noc_GEM63XLProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8a30-862f-7614-b956-2d3a8d918b39" xlink:to="loc_noc_GEM63XLProgramMember_019f8a30-862f-71a9-bd5a-07ef89566725" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInAccountingEstimateByTypeAxis_019f8a30-862f-7e43-94ab-e57eeb7669e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ChangeInAccountingEstimateByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfChangeInAccountingEstimateTable_019f8a30-862f-78df-ad5d-8790b018eaf6" xlink:to="loc_us-gaap_ChangeInAccountingEstimateByTypeAxis_019f8a30-862f-7e43-94ab-e57eeb7669e5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInAccountingEstimateTypeDomain_019f8a30-862f-7e43-94ab-e57eeb7669e5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ChangeInAccountingEstimateTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ChangeInAccountingEstimateByTypeAxis_019f8a30-862f-7e43-94ab-e57eeb7669e5" xlink:to="loc_us-gaap_ChangeInAccountingEstimateTypeDomain_019f8a30-862f-7e43-94ab-e57eeb7669e5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInAccountingEstimateTypeDomain_019f8a30-862f-70fc-9118-e9d8eee902b0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ChangeInAccountingEstimateTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ChangeInAccountingEstimateByTypeAxis_019f8a30-862f-7e43-94ab-e57eeb7669e5" xlink:to="loc_us-gaap_ChangeInAccountingEstimateTypeDomain_019f8a30-862f-70fc-9118-e9d8eee902b0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractsAccountedForUnderPercentageOfCompletionMember_019f8a30-862f-747b-98c0-d54ff5541de1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractsAccountedForUnderPercentageOfCompletionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingEstimateTypeDomain_019f8a30-862f-70fc-9118-e9d8eee902b0" xlink:to="loc_us-gaap_ContractsAccountedForUnderPercentageOfCompletionMember_019f8a30-862f-747b-98c0-d54ff5541de1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-862f-756e-8fd9-53bf92618650" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfChangeInAccountingEstimateTable_019f8a30-862f-78df-ad5d-8790b018eaf6" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-862f-756e-8fd9-53bf92618650" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8a30-862f-756e-8fd9-53bf92618650_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-862f-756e-8fd9-53bf92618650" xlink:to="loc_us-gaap_SegmentDomain_019f8a30-862f-756e-8fd9-53bf92618650_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8a30-862f-7a43-9a6c-82be7b5958a4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-862f-756e-8fd9-53bf92618650" xlink:to="loc_us-gaap_SegmentDomain_019f8a30-862f-7a43-9a6c-82be7b5958a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_AeronauticsSystemsMember_019f8a30-862f-7580-a643-7105fba3d789" xlink:href="noc-20260930.xsd#noc_AeronauticsSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-862f-7a43-9a6c-82be7b5958a4" xlink:to="loc_noc_AeronauticsSystemsMember_019f8a30-862f-7580-a643-7105fba3d789" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_DefenseSystemsMember_019f8a30-862f-7d0d-a539-10c7c3e43cb5" xlink:href="noc-20260930.xsd#noc_DefenseSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-862f-7a43-9a6c-82be7b5958a4" xlink:to="loc_noc_DefenseSystemsMember_019f8a30-862f-7d0d-a539-10c7c3e43cb5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_MissionSystemsMember_019f8a30-862f-729d-a29b-a0f2e777ad82" xlink:href="noc-20260930.xsd#noc_MissionSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-862f-7a43-9a6c-82be7b5958a4" xlink:to="loc_noc_MissionSystemsMember_019f8a30-862f-729d-a29b-a0f2e777ad82" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_SpaceSystemsMember_019f8a30-862f-777a-8be8-0303ef729e7b" xlink:href="noc-20260930.xsd#noc_SpaceSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-862f-7a43-9a6c-82be7b5958a4" xlink:to="loc_noc_SpaceSystemsMember_019f8a30-862f-777a-8be8-0303ef729e7b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod_019f8a30-862f-7865-9168-3509e46afeb7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingEstimateLineItems_019f8a30-862f-73c3-8128-e3c2c653f9db" xlink:to="loc_us-gaap_ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod_019f8a30-862f-7865-9168-3509e46afeb7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019f8a30-862f-7a7e-b90b-2322e1073e27" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingEstimateLineItems_019f8a30-862f-73c3-8128-e3c2c653f9db" xlink:to="loc_us-gaap_OperatingIncomeLoss_019f8a30-862f-7a7e-b90b-2322e1073e27" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019f8a30-862f-7ea3-b079-83efed2008c1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingEstimateLineItems_019f8a30-862f-73c3-8128-e3c2c653f9db" xlink:to="loc_us-gaap_NetIncomeLoss_019f8a30-862f-7ea3-b079-83efed2008c1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_019f8a30-862f-7633-93a5-f8b6b909d619" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingEstimateLineItems_019f8a30-862f-73c3-8128-e3c2c653f9db" xlink:to="loc_us-gaap_EarningsPerShareDiluted_019f8a30-862f-7633-93a5-f8b6b909d619" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyLossInPeriod_019f8a30-862f-7f56-8351-f973d4b307a5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyLossInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingEstimateLineItems_019f8a30-862f-73c3-8128-e3c2c653f9db" xlink:to="loc_us-gaap_LossContingencyLossInPeriod_019f8a30-862f-7f56-8351-f973d4b307a5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyAccrualAtCarryingValue_019f8a30-862f-7473-b475-77e3bbce9ba4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyAccrualAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingEstimateLineItems_019f8a30-862f-73c3-8128-e3c2c653f9db" xlink:to="loc_us-gaap_LossContingencyAccrualAtCarryingValue_019f8a30-862f-7473-b475-77e3bbce9ba4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInAccountingEstimateLineItems_019f8a30-86d1-7f39-bd0f-8eec9b3af461" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ChangeInAccountingEstimateLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfChangeInAccountingEstimateTable_019f8a30-862f-77e8-8eff-b9e30e44f61a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfChangeInAccountingEstimateTable"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-862f-7077-8a26-9b21c07f1ad9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8a30-862f-7077-8a26-9b21c07f1ad9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8a30-862f-7422-9f2e-6acaab69a4c2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_DefenseSystemsMember_019f8a30-862f-77c2-ad06-8957c103f828" xlink:href="noc-20260930.xsd#noc_DefenseSystemsMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_MissionSystemsMember_019ffcfb-432e-7969-b18f-960367138dbf" xlink:href="noc-20260930.xsd#noc_MissionSystemsMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_AeronauticsSystemsMember_01a01551-d643-7280-b19a-515852e1af3f" xlink:href="noc-20260930.xsd#noc_AeronauticsSystemsMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019f8a30-862f-724e-9f24-ebb9d0696153" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f8a30-862f-724e-9f24-ebb9d0696153_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f8a30-862f-7f5c-bd99-031f1a53ea21" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_GEM63XLProgramMember_019f8a30-86d1-70a5-b065-79db2cfd9927" xlink:href="noc-20260930.xsd#noc_GEM63XLProgramMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_StandInAttackWeaponProgramMember_019f8a30-86d1-7fa2-ae81-82715a4841f3" xlink:href="noc-20260930.xsd#noc_StandInAttackWeaponProgramMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_RestrictedMicroelectronicsPortfolioMember_019ffcfa-ed0e-7990-acc3-5a9dc947a410" xlink:href="noc-20260930.xsd#noc_RestrictedMicroelectronicsPortfolioMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_B21ProgramLRIPOptions12Member_01a01551-9380-7637-b96f-a66fc90e5730" xlink:href="noc-20260930.xsd#noc_B21ProgramLRIPOptions12Member"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019ffcfa-ed0e-7e28-b777-acfebd2e052b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/SummaryofSignificantAccountingPoliciesUnauditedBacklogandContractAssetsandLiabilitiesDetails3" xlink:type="simple" xlink:href="noc-20260930.xsd#SummaryofSignificantAccountingPoliciesUnauditedBacklogandContractAssetsandLiabilitiesDetails3"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/SummaryofSignificantAccountingPoliciesUnauditedBacklogandContractAssetsandLiabilitiesDetails3" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_noc_BacklogAwardsAndRelatedAdjustmentsLineItems_019f8a30-86d1-74b6-982a-68f97ce4ec58" xlink:href="noc-20260930.xsd#noc_BacklogAwardsAndRelatedAdjustmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_BacklogAwardsAndRelatedAdjustmentsTable_019f8a30-86d1-7671-a1ef-3f52a15116ba" xlink:href="noc-20260930.xsd#noc_BacklogAwardsAndRelatedAdjustmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_noc_BacklogAwardsAndRelatedAdjustmentsLineItems_019f8a30-86d1-74b6-982a-68f97ce4ec58" xlink:to="loc_noc_BacklogAwardsAndRelatedAdjustmentsTable_019f8a30-86d1-7671-a1ef-3f52a15116ba" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d1-7240-9236-0ca14a3aedb8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_noc_BacklogAwardsAndRelatedAdjustmentsTable_019f8a30-86d1-7671-a1ef-3f52a15116ba" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d1-7240-9236-0ca14a3aedb8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8a30-86d1-7240-9236-0ca14a3aedb8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d1-7240-9236-0ca14a3aedb8" xlink:to="loc_us-gaap_SegmentDomain_019f8a30-86d1-7240-9236-0ca14a3aedb8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8a30-86d1-7ba7-8983-e78296f1b0e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d1-7240-9236-0ca14a3aedb8" xlink:to="loc_us-gaap_SegmentDomain_019f8a30-86d1-7ba7-8983-e78296f1b0e1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_DefenseSystemsMember_019f8a30-86d1-7677-84bc-aa3e359d0e4a" xlink:href="noc-20260930.xsd#noc_DefenseSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d1-7ba7-8983-e78296f1b0e1" xlink:to="loc_noc_DefenseSystemsMember_019f8a30-86d1-7677-84bc-aa3e359d0e4a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_SpaceSystemsMember_019f8a30-86d1-7439-b5f5-30ac825de021" xlink:href="noc-20260930.xsd#noc_SpaceSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d1-7ba7-8983-e78296f1b0e1" xlink:to="loc_noc_SpaceSystemsMember_019f8a30-86d1-7439-b5f5-30ac825de021" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019f8a30-86d1-78cd-8622-05c108c89ee7" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_noc_BacklogAwardsAndRelatedAdjustmentsTable_019f8a30-86d1-7671-a1ef-3f52a15116ba" xlink:to="loc_srt_ProductOrServiceAxis_019f8a30-86d1-78cd-8622-05c108c89ee7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f8a30-86d1-78cd-8622-05c108c89ee7_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019f8a30-86d1-78cd-8622-05c108c89ee7" xlink:to="loc_srt_ProductsAndServicesDomain_019f8a30-86d1-78cd-8622-05c108c89ee7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f8a30-86d1-780e-b570-30b1e695a827" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019f8a30-86d1-78cd-8622-05c108c89ee7" xlink:to="loc_srt_ProductsAndServicesDomain_019f8a30-86d1-780e-b570-30b1e695a827" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_TrainingServicesBusinessMember_019f8a30-86d1-762b-857e-6c21ef1d3891" xlink:href="noc-20260930.xsd#noc_TrainingServicesBusinessMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8a30-86d1-780e-b570-30b1e695a827" xlink:to="loc_noc_TrainingServicesBusinessMember_019f8a30-86d1-762b-857e-6c21ef1d3891" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_019f8a30-86d1-7846-bb35-f157fc3b46a4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_noc_BacklogAwardsAndRelatedAdjustmentsLineItems_019f8a30-86d1-74b6-982a-68f97ce4ec58" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_019f8a30-86d1-7846-bb35-f157fc3b46a4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_BacklogReductionDueToDivestiture_019f8a30-86d1-75b6-9cf5-148bcedb6f1d" xlink:href="noc-20260930.xsd#noc_BacklogReductionDueToDivestiture"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_noc_BacklogAwardsAndRelatedAdjustmentsLineItems_019f8a30-86d1-74b6-982a-68f97ce4ec58" xlink:to="loc_noc_BacklogReductionDueToDivestiture_019f8a30-86d1-75b6-9cf5-148bcedb6f1d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8a30-86d1-733a-8fc3-63b04aed8c51" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019f8a30-86d1-726a-bd55-509e44c7a15d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8a30-86d1-733a-8fc3-63b04aed8c51" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019f8a30-86d1-726a-bd55-509e44c7a15d" xlink:type="arc" order="2" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_019f8a30-86d1-743c-a5e3-b65fd69c7d35" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019f8a30-86d1-726a-bd55-509e44c7a15d" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_019f8a30-86d1-743c-a5e3-b65fd69c7d35" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019f8a30-86d1-79df-bd43-d370016b6779" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8a30-86d1-733a-8fc3-63b04aed8c51" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019f8a30-86d1-79df-bd43-d370016b6779" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019f8a30-86d1-7a36-aeef-3fe1a6ac5a34" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8a30-86d1-733a-8fc3-63b04aed8c51" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019f8a30-86d1-7a36-aeef-3fe1a6ac5a34" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionExplanation_019f8a30-86d1-76af-82e7-6fee347541de" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionExplanation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8a30-86d1-733a-8fc3-63b04aed8c51" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionExplanation_019f8a30-86d1-76af-82e7-6fee347541de" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/SummaryofSignificantAccountingPoliciesUnauditedBacklogandContractAssetsandLiabilitiesDetails3_1" xlink:type="simple" xlink:href="noc-20260930.xsd#SummaryofSignificantAccountingPoliciesUnauditedBacklogandContractAssetsandLiabilitiesDetails3_1"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/SummaryofSignificantAccountingPoliciesUnauditedBacklogandContractAssetsandLiabilitiesDetails3_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8a30-86d1-733a-8fc3-63b04aed8c51" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019f8a30-86d1-726a-bd55-509e44c7a15d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8a30-86d1-733a-8fc3-63b04aed8c51" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_019f8a30-86d1-726a-bd55-509e44c7a15d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019f8a30-86d1-79df-bd43-d370016b6779" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8a30-86d1-733a-8fc3-63b04aed8c51" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_019f8a30-86d1-79df-bd43-d370016b6779" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019f8a30-86d1-7a36-aeef-3fe1a6ac5a34" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8a30-86d1-733a-8fc3-63b04aed8c51" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_019f8a30-86d1-7a36-aeef-3fe1a6ac5a34" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionExplanation_019f8a30-86d1-76af-82e7-6fee347541de" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionExplanation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_019f8a30-86d1-733a-8fc3-63b04aed8c51" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionExplanation_019f8a30-86d1-76af-82e7-6fee347541de" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/SummaryofSignificantAccountingPoliciesUnauditedPropertyPlantandEquipmentDetails4" xlink:type="simple" xlink:href="noc-20260930.xsd#SummaryofSignificantAccountingPoliciesUnauditedPropertyPlantandEquipmentDetails4"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/SummaryofSignificantAccountingPoliciesUnauditedPropertyPlantandEquipmentDetails4" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019f8a30-86d1-7364-ad6c-4c1537c614d5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019f8a30-86d1-72cb-a261-3556ad0e6fd0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019f8a30-86d1-7364-ad6c-4c1537c614d5" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019f8a30-86d1-72cb-a261-3556ad0e6fd0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019f8a30-86d1-7d04-b66d-7fbe19ad540c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019f8a30-86d1-72cb-a261-3556ad0e6fd0" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019f8a30-86d1-7d04-b66d-7fbe19ad540c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f8a30-86d1-7d04-b66d-7fbe19ad540c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019f8a30-86d1-7d04-b66d-7fbe19ad540c" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f8a30-86d1-7d04-b66d-7fbe19ad540c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f8a30-86d1-7f5d-99ec-64a14d380653" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019f8a30-86d1-7d04-b66d-7fbe19ad540c" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f8a30-86d1-7f5d-99ec-64a14d380653" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_019f8a30-86d1-7612-8ba9-ade2c3155e30" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f8a30-86d1-7f5d-99ec-64a14d380653" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_019f8a30-86d1-7612-8ba9-ade2c3155e30" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SoftwareAndSoftwareDevelopmentCostsMember_019f8a30-86d1-7748-a42b-91a238b8708a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SoftwareAndSoftwareDevelopmentCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f8a30-86d1-7f5d-99ec-64a14d380653" xlink:to="loc_us-gaap_SoftwareAndSoftwareDevelopmentCostsMember_019f8a30-86d1-7748-a42b-91a238b8708a" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/EarningsPerShareShareRepurchasesandDividendsonCommonStockUnauditedShareRepurchasesDetails2" xlink:type="simple" xlink:href="noc-20260930.xsd#EarningsPerShareShareRepurchasesandDividendsonCommonStockUnauditedShareRepurchasesDetails2"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/EarningsPerShareShareRepurchasesandDividendsonCommonStockUnauditedShareRepurchasesDetails2" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019f8a30-86d1-779d-a1ae-2e14ef02c597" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityClassOfTreasuryStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfTreasuryStockTable_019f8a30-86d1-7a49-9b1a-1be8c18a1f26" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfTreasuryStockTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019f8a30-86d1-779d-a1ae-2e14ef02c597" xlink:to="loc_us-gaap_ClassOfTreasuryStockTable_019f8a30-86d1-7a49-9b1a-1be8c18a1f26" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramAxis_019f8a30-86d1-7cad-8b0f-bfa6967fb501" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ClassOfTreasuryStockTable_019f8a30-86d1-7a49-9b1a-1be8c18a1f26" xlink:to="loc_srt_ShareRepurchaseProgramAxis_019f8a30-86d1-7cad-8b0f-bfa6967fb501" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_019f8a30-86d1-7cad-8b0f-bfa6967fb501_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ShareRepurchaseProgramAxis_019f8a30-86d1-7cad-8b0f-bfa6967fb501" xlink:to="loc_srt_ShareRepurchaseProgramDomain_019f8a30-86d1-7cad-8b0f-bfa6967fb501_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_019f8a30-86d1-7042-abc2-f3722d56cbfa" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ShareRepurchaseProgramAxis_019f8a30-86d1-7cad-8b0f-bfa6967fb501" xlink:to="loc_srt_ShareRepurchaseProgramDomain_019f8a30-86d1-7042-abc2-f3722d56cbfa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_December2023ShareRepurchaseProgramMember_019f8a30-86d1-7d97-84f4-2660b7435dfd" xlink:href="noc-20260930.xsd#noc_December2023ShareRepurchaseProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_019f8a30-86d1-7042-abc2-f3722d56cbfa" xlink:to="loc_noc_December2023ShareRepurchaseProgramMember_019f8a30-86d1-7d97-84f4-2660b7435dfd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_December2024ShareRepurchaseProgramMember_019f8a30-86d1-7a87-8364-04b8c5cd6e3f" xlink:href="noc-20260930.xsd#noc_December2024ShareRepurchaseProgramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_019f8a30-86d1-7042-abc2-f3722d56cbfa" xlink:to="loc_noc_December2024ShareRepurchaseProgramMember_019f8a30-86d1-7a87-8364-04b8c5cd6e3f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StockRepurchaseProgramAuthorizedAmount1_019f8a30-86d1-76ca-a69c-c465857b08a9" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StockRepurchaseProgramAuthorizedAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019f8a30-86d1-779d-a1ae-2e14ef02c597" xlink:to="loc_srt_StockRepurchaseProgramAuthorizedAmount1_019f8a30-86d1-76ca-a69c-c465857b08a9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesRetired_019f8a30-86d1-70eb-87c0-a32676eec4e0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockSharesRetired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019f8a30-86d1-779d-a1ae-2e14ef02c597" xlink:to="loc_us-gaap_TreasuryStockSharesRetired_019f8a30-86d1-70eb-87c0-a32676eec4e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_019f8a30-86d1-76b7-9ec2-049200fcb97a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockAcquiredAverageCostPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019f8a30-86d1-779d-a1ae-2e14ef02c597" xlink:to="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_019f8a30-86d1-76b7-9ec2-049200fcb97a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_A2022RepurchaseProgramCompletionDate_019f8a30-86d1-7dfa-902f-0b32593879f7" xlink:href="noc-20260930.xsd#noc_A2022RepurchaseProgramCompletionDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019f8a30-86d1-779d-a1ae-2e14ef02c597" xlink:to="loc_noc_A2022RepurchaseProgramCompletionDate_019f8a30-86d1-7dfa-902f-0b32593879f7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_A2023RepurchaseProgramCompletionDate_019f8a30-86d1-7792-bea7-af5fd0f95bf2" xlink:href="noc-20260930.xsd#noc_A2023RepurchaseProgramCompletionDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019f8a30-86d1-779d-a1ae-2e14ef02c597" xlink:to="loc_noc_A2023RepurchaseProgramCompletionDate_019f8a30-86d1-7792-bea7-af5fd0f95bf2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_019f8a30-86d1-7efd-b655-82b7ce89eb91" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019f8a30-86d1-779d-a1ae-2e14ef02c597" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_019f8a30-86d1-7efd-b655-82b7ce89eb91" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredParValueMethod_019f8a30-86d1-7509-af84-38fa59a7f76f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockValueAcquiredParValueMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019f8a30-86d1-779d-a1ae-2e14ef02c597" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredParValueMethod_019f8a30-86d1-7509-af84-38fa59a7f76f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_ShareRepurchasesTableAbstract_019f8a30-86d1-7434-9299-6871268bd73d" xlink:href="noc-20260930.xsd#noc_ShareRepurchasesTableAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019f8a30-86d1-779d-a1ae-2e14ef02c597" xlink:to="loc_noc_ShareRepurchasesTableAbstract_019f8a30-86d1-7434-9299-6871268bd73d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_019f8a30-86d1-789e-8d0a-602d4bf5367f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_noc_ShareRepurchasesTableAbstract_019f8a30-86d1-7434-9299-6871268bd73d" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_019f8a30-86d1-789e-8d0a-602d4bf5367f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_019f8a30-86d1-7d75-bbbd-bb8c054e3960" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityClassOfTreasuryStockLineItems_019f8a30-86d1-779d-a1ae-2e14ef02c597" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_019f8a30-86d1-7d75-bbbd-bb8c054e3960" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcceleratedShareRepurchasesLineItems_019f8a30-86d1-7ed4-b238-269e2c9bcd75" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AcceleratedShareRepurchasesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcceleratedShareRepurchasesTable_019f8a30-86d1-759d-b93f-11eff166d1be" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AcceleratedShareRepurchasesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AcceleratedShareRepurchasesLineItems_019f8a30-86d1-7ed4-b238-269e2c9bcd75" xlink:to="loc_us-gaap_AcceleratedShareRepurchasesTable_019f8a30-86d1-759d-b93f-11eff166d1be" xlink:type="arc" order="2" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcceleratedShareRepurchasesDateAxis_019f8a30-86d1-7676-b7b2-fed9424f4234" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AcceleratedShareRepurchasesDateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AcceleratedShareRepurchasesTable_019f8a30-86d1-759d-b93f-11eff166d1be" xlink:to="loc_us-gaap_AcceleratedShareRepurchasesDateAxis_019f8a30-86d1-7676-b7b2-fed9424f4234" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcceleratedShareRepurchasesDateDomain_019f8a30-86d1-7676-b7b2-fed9424f4234_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AcceleratedShareRepurchasesDateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AcceleratedShareRepurchasesDateAxis_019f8a30-86d1-7676-b7b2-fed9424f4234" xlink:to="loc_us-gaap_AcceleratedShareRepurchasesDateDomain_019f8a30-86d1-7676-b7b2-fed9424f4234_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcceleratedShareRepurchasesDateDomain_019f8a30-86d1-7f3b-a972-d008bfe152da" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AcceleratedShareRepurchasesDateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AcceleratedShareRepurchasesDateAxis_019f8a30-86d1-7676-b7b2-fed9424f4234" xlink:to="loc_us-gaap_AcceleratedShareRepurchasesDateDomain_019f8a30-86d1-7f3b-a972-d008bfe152da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcceleratedShareRepurchasesCashOrStockSettlement_019f8a30-86d1-7610-a804-86fc12e19813" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AcceleratedShareRepurchasesCashOrStockSettlement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcceleratedShareRepurchasesLineItems_019f8a30-86d1-7ed4-b238-269e2c9bcd75" xlink:to="loc_us-gaap_AcceleratedShareRepurchasesCashOrStockSettlement_019f8a30-86d1-7610-a804-86fc12e19813" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcceleratedShareRepurchasesSettlementPaymentOrReceipt_019f8a30-86d1-74ed-9a6d-3d669eb06d99" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AcceleratedShareRepurchasesSettlementPaymentOrReceipt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcceleratedShareRepurchasesLineItems_019f8a30-86d1-7ed4-b238-269e2c9bcd75" xlink:to="loc_us-gaap_AcceleratedShareRepurchasesSettlementPaymentOrReceipt_019f8a30-86d1-74ed-9a6d-3d669eb06d99" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_AcceleratedShareRepurchaseInitialReceiptShares_019f8a30-86d1-7874-8430-1414302daf5b" xlink:href="noc-20260930.xsd#noc_AcceleratedShareRepurchaseInitialReceiptShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcceleratedShareRepurchasesLineItems_019f8a30-86d1-7ed4-b238-269e2c9bcd75" xlink:to="loc_noc_AcceleratedShareRepurchaseInitialReceiptShares_019f8a30-86d1-7874-8430-1414302daf5b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_019f8a30-86d1-73e3-8efc-bed4c69f5370" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcceleratedShareRepurchasesLineItems_019f8a30-86d1-7ed4-b238-269e2c9bcd75" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_019f8a30-86d1-73e3-8efc-bed4c69f5370" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcceleratedShareRepurchasesAdjustmentToRecordedAmount_019f8a30-86d1-7c73-b065-bc9051b8a2c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AcceleratedShareRepurchasesAdjustmentToRecordedAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcceleratedShareRepurchasesLineItems_019f8a30-86d1-7ed4-b238-269e2c9bcd75" xlink:to="loc_us-gaap_AcceleratedShareRepurchasesAdjustmentToRecordedAmount_019f8a30-86d1-7c73-b065-bc9051b8a2c4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcceleratedShareRepurchasesFinalPricePaidPerShare_019f8a30-86d1-76a9-9390-635e8d659e9c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AcceleratedShareRepurchasesFinalPricePaidPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcceleratedShareRepurchasesLineItems_019f8a30-86d1-7ed4-b238-269e2c9bcd75" xlink:to="loc_us-gaap_AcceleratedShareRepurchasesFinalPricePaidPerShare_019f8a30-86d1-76a9-9390-635e8d659e9c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_AcceleratedShareRepurchaseFinalReceiptShares_019f8a30-86d1-7170-bf96-74659bad7d60" xlink:href="noc-20260930.xsd#noc_AcceleratedShareRepurchaseFinalReceiptShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcceleratedShareRepurchasesLineItems_019f8a30-86d1-7ed4-b238-269e2c9bcd75" xlink:to="loc_noc_AcceleratedShareRepurchaseFinalReceiptShares_019f8a30-86d1-7170-bf96-74659bad7d60" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/InventoryUnauditedDetails" xlink:type="simple" xlink:href="noc-20260930.xsd#InventoryUnauditedDetails"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/InventoryUnauditedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryLineItems_019f8a30-86d1-7333-9b8f-c2a5a5025ba9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryCurrentTable_019f8a30-86d1-79ce-b189-3468718863f9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryCurrentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_InventoryLineItems_019f8a30-86d1-7333-9b8f-c2a5a5025ba9" xlink:to="loc_us-gaap_InventoryCurrentTable_019f8a30-86d1-79ce-b189-3468718863f9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d1-7743-ae15-ac7002a073b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InventoryCurrentTable_019f8a30-86d1-79ce-b189-3468718863f9" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d1-7743-ae15-ac7002a073b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8a30-86d1-7743-ae15-ac7002a073b5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d1-7743-ae15-ac7002a073b5" xlink:to="loc_us-gaap_SegmentDomain_019f8a30-86d1-7743-ae15-ac7002a073b5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8a30-86d1-7ae5-a24d-3efa5f46dbb6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d1-7743-ae15-ac7002a073b5" xlink:to="loc_us-gaap_SegmentDomain_019f8a30-86d1-7ae5-a24d-3efa5f46dbb6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_019f8a30-86d1-7f9e-9e47-58f0b6f1c01f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InventoryCurrentTable_019f8a30-86d1-79ce-b189-3468718863f9" xlink:to="loc_srt_MajorCustomersAxis_019f8a30-86d1-7f9e-9e47-58f0b6f1c01f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_019f8a30-86d1-7f9e-9e47-58f0b6f1c01f_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_019f8a30-86d1-7f9e-9e47-58f0b6f1c01f" xlink:to="loc_srt_NameOfMajorCustomerDomain_019f8a30-86d1-7f9e-9e47-58f0b6f1c01f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_019f8a30-86d1-77d7-bb4c-68545a094139" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_019f8a30-86d1-7f9e-9e47-58f0b6f1c01f" xlink:to="loc_srt_NameOfMajorCustomerDomain_019f8a30-86d1-77d7-bb4c-68545a094139" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryRawMaterialsNetOfReserves_019f8a30-86d1-7fe5-8bed-0b9cd9015945" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryRawMaterialsNetOfReserves"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_019f8a30-86d1-7333-9b8f-c2a5a5025ba9" xlink:to="loc_us-gaap_InventoryRawMaterialsNetOfReserves_019f8a30-86d1-7fe5-8bed-0b9cd9015945" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryWorkInProcessNetOfReserves_019f8a30-86d1-7a9b-b06f-0630a7fc045e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryWorkInProcessNetOfReserves"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_019f8a30-86d1-7333-9b8f-c2a5a5025ba9" xlink:to="loc_us-gaap_InventoryWorkInProcessNetOfReserves_019f8a30-86d1-7a9b-b06f-0630a7fc045e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryFinishedGoodsNetOfReserves_019f8a30-86d1-79f1-817e-efd6c868c256" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryFinishedGoodsNetOfReserves"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_019f8a30-86d1-7333-9b8f-c2a5a5025ba9" xlink:to="loc_us-gaap_InventoryFinishedGoodsNetOfReserves_019f8a30-86d1-79f1-817e-efd6c868c256" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNet_019f8a30-86d1-7a59-8642-86845852f46a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_019f8a30-86d1-7333-9b8f-c2a5a5025ba9" xlink:to="loc_us-gaap_InventoryNet_019f8a30-86d1-7a59-8642-86845852f46a" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/IncomeTaxesUnauditedEffectiveIncomeTaxRateReconciliationDetails1" xlink:type="simple" xlink:href="noc-20260930.xsd#IncomeTaxesUnauditedEffectiveIncomeTaxRateReconciliationDetails1"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/IncomeTaxesUnauditedEffectiveIncomeTaxRateReconciliationDetails1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_noc_EffectOfNewTaxLegislationLineItems_019f8a30-86d1-7e2a-9201-c8366074b9d3" xlink:href="noc-20260930.xsd#noc_EffectOfNewTaxLegislationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_EffectOfNewTaxLegislationTable_019f8a30-86d1-71b2-957c-a1c0627a6ef9" xlink:href="noc-20260930.xsd#noc_EffectOfNewTaxLegislationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_noc_EffectOfNewTaxLegislationLineItems_019f8a30-86d1-7e2a-9201-c8366074b9d3" xlink:to="loc_noc_EffectOfNewTaxLegislationTable_019f8a30-86d1-71b2-957c-a1c0627a6ef9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardAxis_019f8a30-86d1-74e5-adb9-90c3d006facf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TaxCreditCarryforwardAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_noc_EffectOfNewTaxLegislationTable_019f8a30-86d1-71b2-957c-a1c0627a6ef9" xlink:to="loc_us-gaap_TaxCreditCarryforwardAxis_019f8a30-86d1-74e5-adb9-90c3d006facf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardNameDomain_019f8a30-86d1-74e5-adb9-90c3d006facf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TaxCreditCarryforwardNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TaxCreditCarryforwardAxis_019f8a30-86d1-74e5-adb9-90c3d006facf" xlink:to="loc_us-gaap_TaxCreditCarryforwardNameDomain_019f8a30-86d1-74e5-adb9-90c3d006facf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardNameDomain_019f8a30-86d1-72e0-83c2-ae6f8c95930f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TaxCreditCarryforwardNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TaxCreditCarryforwardAxis_019f8a30-86d1-74e5-adb9-90c3d006facf" xlink:to="loc_us-gaap_TaxCreditCarryforwardNameDomain_019f8a30-86d1-72e0-83c2-ae6f8c95930f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_CorporateAlternativeMinimumTaxMember_019f8a30-86d1-71ee-87e5-432baaef6c31" xlink:href="noc-20260930.xsd#noc_CorporateAlternativeMinimumTaxMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxCreditCarryforwardNameDomain_019f8a30-86d1-72e0-83c2-ae6f8c95930f" xlink:to="loc_noc_CorporateAlternativeMinimumTaxMember_019f8a30-86d1-71ee-87e5-432baaef6c31" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_EffectOfTaxLegislationEnactedAxis_019f8a30-86d1-7926-be61-dd8fbfdc0170" xlink:href="noc-20260930.xsd#noc_EffectOfTaxLegislationEnactedAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_noc_EffectOfNewTaxLegislationTable_019f8a30-86d1-71b2-957c-a1c0627a6ef9" xlink:to="loc_noc_EffectOfTaxLegislationEnactedAxis_019f8a30-86d1-7926-be61-dd8fbfdc0170" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_EffectOfTaxLegislationEnactedDuringThePeriodDomain_019f8a30-86d1-7926-be61-dd8fbfdc0170_default" xlink:href="noc-20260930.xsd#noc_EffectOfTaxLegislationEnactedDuringThePeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_noc_EffectOfTaxLegislationEnactedAxis_019f8a30-86d1-7926-be61-dd8fbfdc0170" xlink:to="loc_noc_EffectOfTaxLegislationEnactedDuringThePeriodDomain_019f8a30-86d1-7926-be61-dd8fbfdc0170_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_EffectOfTaxLegislationEnactedDuringThePeriodDomain_019f8a30-86d1-796e-a2fe-acc27879b591" xlink:href="noc-20260930.xsd#noc_EffectOfTaxLegislationEnactedDuringThePeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_noc_EffectOfTaxLegislationEnactedAxis_019f8a30-86d1-7926-be61-dd8fbfdc0170" xlink:to="loc_noc_EffectOfTaxLegislationEnactedDuringThePeriodDomain_019f8a30-86d1-796e-a2fe-acc27879b591" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_OBBBAMember_019f8a30-86d1-73d8-b9ef-a13d2e25782c" xlink:href="noc-20260930.xsd#noc_OBBBAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_noc_EffectOfTaxLegislationEnactedDuringThePeriodDomain_019f8a30-86d1-796e-a2fe-acc27879b591" xlink:to="loc_noc_OBBBAMember_019f8a30-86d1-73d8-b9ef-a13d2e25782c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_IRSNotice20267Member_019f8a30-86d1-79e2-b86b-4e9b9187eb96" xlink:href="noc-20260930.xsd#noc_IRSNotice20267Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_noc_EffectOfTaxLegislationEnactedDuringThePeriodDomain_019f8a30-86d1-796e-a2fe-acc27879b591" xlink:to="loc_noc_IRSNotice20267Member_019f8a30-86d1-79e2-b86b-4e9b9187eb96" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsAlternativeMinimumTax_019f8a30-86d1-7c48-8324-a19e477057a3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsAlternativeMinimumTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_noc_EffectOfNewTaxLegislationLineItems_019f8a30-86d1-7e2a-9201-c8366074b9d3" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsAlternativeMinimumTax_019f8a30-86d1-7c48-8324-a19e477057a3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInDeferredIncomeTaxes_019f8a30-86d1-715d-b71c-799a27387cba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInDeferredIncomeTaxes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_noc_EffectOfNewTaxLegislationLineItems_019f8a30-86d1-7e2a-9201-c8366074b9d3" xlink:to="loc_us-gaap_IncreaseDecreaseInDeferredIncomeTaxes_019f8a30-86d1-715d-b71c-799a27387cba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxContingencyLineItems_019f8a30-86d1-7547-802e-93d56394859e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxContingencyLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable_019f8a30-86d1-7330-a87b-f2e36be7c066" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019f8a30-86d1-7547-802e-93d56394859e" xlink:to="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable_019f8a30-86d1-7330-a87b-f2e36be7c066" xlink:type="arc" order="2" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityNameAxis_019f8a30-86d1-7fc7-89ea-8e788f57d354" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxAuthorityNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable_019f8a30-86d1-7330-a87b-f2e36be7c066" xlink:to="loc_us-gaap_IncomeTaxAuthorityNameAxis_019f8a30-86d1-7fc7-89ea-8e788f57d354" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityNameDomain_019f8a30-86d1-7fc7-89ea-8e788f57d354_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxAuthorityNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameAxis_019f8a30-86d1-7fc7-89ea-8e788f57d354" xlink:to="loc_us-gaap_IncomeTaxAuthorityNameDomain_019f8a30-86d1-7fc7-89ea-8e788f57d354_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityNameDomain_019f8a30-86d1-78a9-afd6-027d579f8c2d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxAuthorityNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameAxis_019f8a30-86d1-7fc7-89ea-8e788f57d354" xlink:to="loc_us-gaap_IncomeTaxAuthorityNameDomain_019f8a30-86d1-78a9-afd6-027d579f8c2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalRevenueServiceIRSMember_019f8a30-86d1-7437-b178-c415c0ce54c5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InternalRevenueServiceIRSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameDomain_019f8a30-86d1-78a9-afd6-027d579f8c2d" xlink:to="loc_us-gaap_InternalRevenueServiceIRSMember_019f8a30-86d1-7437-b178-c415c0ce54c5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReasonablyPossibleSignificantChangeInUnrecognizedTaxBenefitsByItemAxis_01a145e9-bb44-7da7-a0cd-fa58a0a086a0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReasonablyPossibleSignificantChangeInUnrecognizedTaxBenefitsByItemAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable_019f8a30-86d1-7330-a87b-f2e36be7c066" xlink:to="loc_us-gaap_ReasonablyPossibleSignificantChangeInUnrecognizedTaxBenefitsByItemAxis_01a145e9-bb44-7da7-a0cd-fa58a0a086a0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleNatureOfUncertaintyDomain_01a145e9-bb44-7da7-a0cd-fa58a0a086a0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleNatureOfUncertaintyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ReasonablyPossibleSignificantChangeInUnrecognizedTaxBenefitsByItemAxis_01a145e9-bb44-7da7-a0cd-fa58a0a086a0" xlink:to="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleNatureOfUncertaintyDomain_01a145e9-bb44-7da7-a0cd-fa58a0a086a0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleNatureOfUncertaintyDomain_01a145e9-bb44-705f-8a2c-119cae73ef12" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleNatureOfUncertaintyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ReasonablyPossibleSignificantChangeInUnrecognizedTaxBenefitsByItemAxis_01a145e9-bb44-7da7-a0cd-fa58a0a086a0" xlink:to="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleNatureOfUncertaintyDomain_01a145e9-bb44-705f-8a2c-119cae73ef12" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_FederalResearchCreditsMember_01a145d4-b451-78a5-9559-f907365e64f1" xlink:href="noc-20260930.xsd#noc_FederalResearchCreditsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleNatureOfUncertaintyDomain_01a145e9-bb44-705f-8a2c-119cae73ef12" xlink:to="loc_noc_FederalResearchCreditsMember_01a145d4-b451-78a5-9559-f907365e64f1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions_019f8a30-86d1-7fcb-9e12-a37b32ea6ee5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019f8a30-86d1-7547-802e-93d56394859e" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions_019f8a30-86d1-7fcb-9e12-a37b32ea6ee5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxAdjustmentsSettlementsAndUnusualProvisions_019f8a30-86d1-7b58-9b9a-ef8dadbe02ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TaxAdjustmentsSettlementsAndUnusualProvisions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_019f8a30-86d1-7547-802e-93d56394859e" xlink:to="loc_us-gaap_TaxAdjustmentsSettlementsAndUnusualProvisions_019f8a30-86d1-7b58-9b9a-ef8dadbe02ae" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/IncomeTaxesUnauditedUnrecognizedTaxBenefitDetails2" xlink:type="simple" xlink:href="noc-20260930.xsd#IncomeTaxesUnauditedUnrecognizedTaxBenefitDetails2"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/IncomeTaxesUnauditedUnrecognizedTaxBenefitDetails2" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems_019f8a30-86d1-7e8d-917d-dc3d3e5ded4a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable_019f8a30-86d1-7ec0-9df7-9b26aa9f5281" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems_019f8a30-86d1-7e8d-917d-dc3d3e5ded4a" xlink:to="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable_019f8a30-86d1-7ec0-9df7-9b26aa9f5281" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_019f8a30-86d1-739a-aa49-b38a7f421291" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleTable_019f8a30-86d1-7ec0-9df7-9b26aa9f5281" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_019f8a30-86d1-739a-aa49-b38a7f421291" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_019f8a30-86d1-739a-aa49-b38a7f421291_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_019f8a30-86d1-739a-aa49-b38a7f421291" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_019f8a30-86d1-739a-aa49-b38a7f421291_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_019f8a30-86d1-7ce4-9d97-de69dd180000" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_019f8a30-86d1-739a-aa49-b38a7f421291" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_019f8a30-86d1-7ce4-9d97-de69dd180000" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalRevenueServiceIRSMember_019f8a30-86d1-7516-acef-5ef9602f1d3b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InternalRevenueServiceIRSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_019f8a30-86d1-7ce4-9d97-de69dd180000" xlink:to="loc_us-gaap_InternalRevenueServiceIRSMember_019f8a30-86d1-7516-acef-5ef9602f1d3b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CaliforniaFranchiseTaxBoardMember_019f8a30-86d1-7bb5-b9ff-64751eeb9728" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CaliforniaFranchiseTaxBoardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_019f8a30-86d1-7ce4-9d97-de69dd180000" xlink:to="loc_us-gaap_CaliforniaFranchiseTaxBoardMember_019f8a30-86d1-7bb5-b9ff-64751eeb9728" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilityForUncertainTaxPositionsCurrent_019f8a30-86d1-75f0-a7d3-2ceab2ba4c88" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilityForUncertainTaxPositionsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems_019f8a30-86d1-7e8d-917d-dc3d3e5ded4a" xlink:to="loc_us-gaap_LiabilityForUncertainTaxPositionsCurrent_019f8a30-86d1-75f0-a7d3-2ceab2ba4c88" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilityForUncertainTaxPositionsNoncurrent_019f8a30-86d1-7599-a544-fafa7069ef46" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilityForUncertainTaxPositionsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems_019f8a30-86d1-7e8d-917d-dc3d3e5ded4a" xlink:to="loc_us-gaap_LiabilityForUncertainTaxPositionsNoncurrent_019f8a30-86d1-7599-a544-fafa7069ef46" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseInUnrecognizedTaxBenefitsIsReasonablyPossible_019f8a30-86d1-7886-9637-298d23620422" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseInUnrecognizedTaxBenefitsIsReasonablyPossible"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems_019f8a30-86d1-7e8d-917d-dc3d3e5ded4a" xlink:to="loc_us-gaap_IncreaseInUnrecognizedTaxBenefitsIsReasonablyPossible_019f8a30-86d1-7886-9637-298d23620422" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsPeriodIncreaseDecrease_019f8a30-86d1-7cca-8a99-c89d36a594ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrecognizedTaxBenefitsPeriodIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems_019f8a30-86d1-7e8d-917d-dc3d3e5ded4a" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsPeriodIncreaseDecrease_019f8a30-86d1-7cca-8a99-c89d36a594ea" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible_019f8a30-86d1-78a6-bafc-9933ef9832b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems_019f8a30-86d1-7e8d-917d-dc3d3e5ded4a" xlink:to="loc_us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible_019f8a30-86d1-78a6-bafc-9933ef9832b8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxAdjustmentsSettlementsAndUnusualProvisions_019f8a30-86d1-74fd-91c0-4c3fc187ccf9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TaxAdjustmentsSettlementsAndUnusualProvisions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleLineItems_019f8a30-86d1-7e8d-917d-dc3d3e5ded4a" xlink:to="loc_us-gaap_TaxAdjustmentsSettlementsAndUnusualProvisions_019f8a30-86d1-74fd-91c0-4c3fc187ccf9" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/FairValueofFinancialInstrumentsUnauditedDetails1" xlink:type="simple" xlink:href="noc-20260930.xsd#FairValueofFinancialInstrumentsUnauditedDetails1"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/FairValueofFinancialInstrumentsUnauditedDetails1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_019f8a30-86d1-7fbf-89e1-1ace9c9d1e0c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_019f8a30-86d1-7219-b04f-2179afce2ac5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_019f8a30-86d1-7fbf-89e1-1ace9c9d1e0c" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_019f8a30-86d1-7219-b04f-2179afce2ac5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019f8a30-86d1-7aff-90d3-520957704263" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_019f8a30-86d1-7219-b04f-2179afce2ac5" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019f8a30-86d1-7aff-90d3-520957704263" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_019f8a30-86d1-7aff-90d3-520957704263_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019f8a30-86d1-7aff-90d3-520957704263" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_019f8a30-86d1-7aff-90d3-520957704263_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_019f8a30-86d1-75c1-8ac3-8f8a84f64fb3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019f8a30-86d1-7aff-90d3-520957704263" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_019f8a30-86d1-75c1-8ac3-8f8a84f64fb3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_019f8a30-86d1-7d80-9b53-79bb531a665d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_019f8a30-86d1-75c1-8ac3-8f8a84f64fb3" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_019f8a30-86d1-7d80-9b53-79bb531a665d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsNonrecurringMember_019f8a30-86d1-797d-b9d9-5005f5c9d9db" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsNonrecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_019f8a30-86d1-75c1-8ac3-8f8a84f64fb3" xlink:to="loc_us-gaap_FairValueMeasurementsNonrecurringMember_019f8a30-86d1-797d-b9d9-5005f5c9d9db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019f8a30-86d1-7cb6-aa6d-495790979811" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_019f8a30-86d1-7219-b04f-2179afce2ac5" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019f8a30-86d1-7cb6-aa6d-495790979811" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f8a30-86d1-7cb6-aa6d-495790979811_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019f8a30-86d1-7cb6-aa6d-495790979811" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f8a30-86d1-7cb6-aa6d-495790979811_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f8a30-86d1-7cf6-abd9-41482b04fc3e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019f8a30-86d1-7cb6-aa6d-495790979811" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f8a30-86d1-7cf6-abd9-41482b04fc3e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_019f8a30-86d1-787d-b3c2-13f32e81ed00" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f8a30-86d1-7cf6-abd9-41482b04fc3e" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_019f8a30-86d1-787d-b3c2-13f32e81ed00" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019f8a30-86d1-7ace-b38c-5c9ef1893cf4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f8a30-86d1-7cf6-abd9-41482b04fc3e" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019f8a30-86d1-7ace-b38c-5c9ef1893cf4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_019f8a30-86d1-7cc4-84aa-8dd96565fe0b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f8a30-86d1-7cf6-abd9-41482b04fc3e" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_019f8a30-86d1-7cc4-84aa-8dd96565fe0b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketableSecurities_019f8a30-86d1-781d-ae48-985ce926fe59" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MarketableSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_019f8a30-86d1-7fbf-89e1-1ace9c9d1e0c" xlink:to="loc_us-gaap_MarketableSecurities_019f8a30-86d1-781d-ae48-985ce926fe59" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet_019f8a30-86d1-7ebb-befb-4f7cc1d6c611" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_019f8a30-86d1-7fbf-89e1-1ace9c9d1e0c" xlink:to="loc_us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet_019f8a30-86d1-7ebb-befb-4f7cc1d6c611" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/AmountsinParagraphsFairValueofFinancialInstrumentsUnauditedDetails2" xlink:type="simple" xlink:href="noc-20260930.xsd#AmountsinParagraphsFairValueofFinancialInstrumentsUnauditedDetails2"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/AmountsinParagraphsFairValueofFinancialInstrumentsUnauditedDetails2" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019f8a30-86d1-7960-9bd9-d0e848660817" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019f8a30-86d1-7cab-b23d-328dfb0f3e22" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8a30-86d1-7960-9bd9-d0e848660817" xlink:to="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019f8a30-86d1-7cab-b23d-328dfb0f3e22" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019f8a30-86d1-77b6-90f4-b68d43f0473d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019f8a30-86d1-7cab-b23d-328dfb0f3e22" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019f8a30-86d1-77b6-90f4-b68d43f0473d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019f8a30-86d1-77b6-90f4-b68d43f0473d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019f8a30-86d1-77b6-90f4-b68d43f0473d" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019f8a30-86d1-77b6-90f4-b68d43f0473d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019f8a30-86d1-764d-80e3-e71215a3cc79" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019f8a30-86d1-77b6-90f4-b68d43f0473d" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019f8a30-86d1-764d-80e3-e71215a3cc79" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeForwardMember_019f8a30-86d1-7c70-a69e-f967e4e0f765" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeForwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019f8a30-86d1-764d-80e3-e71215a3cc79" xlink:to="loc_us-gaap_ForeignExchangeForwardMember_019f8a30-86d1-7c70-a69e-f967e4e0f765" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_019f8a30-86d1-7f21-b0dd-20efca73f39d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_019f8a30-86d1-7cab-b23d-328dfb0f3e22" xlink:to="loc_us-gaap_HedgingDesignationAxis_019f8a30-86d1-7f21-b0dd-20efca73f39d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019f8a30-86d1-7f21-b0dd-20efca73f39d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_019f8a30-86d1-7f21-b0dd-20efca73f39d" xlink:to="loc_us-gaap_HedgingDesignationDomain_019f8a30-86d1-7f21-b0dd-20efca73f39d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019f8a30-86d1-7096-9ad7-037222480bc4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_019f8a30-86d1-7f21-b0dd-20efca73f39d" xlink:to="loc_us-gaap_HedgingDesignationDomain_019f8a30-86d1-7096-9ad7-037222480bc4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019f8a30-86d1-77ac-9e48-fc1719d53f45" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019f8a30-86d1-7096-9ad7-037222480bc4" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019f8a30-86d1-77ac-9e48-fc1719d53f45" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_019f8a30-86d1-712b-8d78-73c423824577" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8a30-86d1-7960-9bd9-d0e848660817" xlink:to="loc_us-gaap_DerivativeNotionalAmount_019f8a30-86d1-712b-8d78-73c423824577" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketableSecuritiesLineItems_019f8a30-86d1-7f4b-92e1-771fbde77c0f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MarketableSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketableSecuritiesTable_019f8a30-86d1-76c3-8445-fbbaf5339768" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MarketableSecuritiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019f8a30-86d1-7f4b-92e1-771fbde77c0f" xlink:to="loc_us-gaap_MarketableSecuritiesTable_019f8a30-86d1-76c3-8445-fbbaf5339768" xlink:type="arc" order="2" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_InvestmentWithIPOAxis_019f8a30-86d1-773c-a872-7cda385cdd61" xlink:href="noc-20260930.xsd#noc_InvestmentWithIPOAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MarketableSecuritiesTable_019f8a30-86d1-76c3-8445-fbbaf5339768" xlink:to="loc_noc_InvestmentWithIPOAxis_019f8a30-86d1-773c-a872-7cda385cdd61" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_InvestmentWithIPODomain_019f8a30-86d1-773c-a872-7cda385cdd61_default" xlink:href="noc-20260930.xsd#noc_InvestmentWithIPODomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_noc_InvestmentWithIPOAxis_019f8a30-86d1-773c-a872-7cda385cdd61" xlink:to="loc_noc_InvestmentWithIPODomain_019f8a30-86d1-773c-a872-7cda385cdd61_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_InvestmentWithIPODomain_019f8a30-86d1-78e4-8c5e-1552e192aad0" xlink:href="noc-20260930.xsd#noc_InvestmentWithIPODomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_noc_InvestmentWithIPOAxis_019f8a30-86d1-773c-a872-7cda385cdd61" xlink:to="loc_noc_InvestmentWithIPODomain_019f8a30-86d1-78e4-8c5e-1552e192aad0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_InvestmentWithIPOMember_019f8a30-86d1-7911-a323-c2c935fc4f5f" xlink:href="noc-20260930.xsd#noc_InvestmentWithIPOMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_noc_InvestmentWithIPODomain_019f8a30-86d1-78e4-8c5e-1552e192aad0" xlink:to="loc_noc_InvestmentWithIPOMember_019f8a30-86d1-7911-a323-c2c935fc4f5f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_InvestmentInPublicCompanyAxis_019f8a30-86d1-7694-a713-bc0bbb954564" xlink:href="noc-20260930.xsd#noc_InvestmentInPublicCompanyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MarketableSecuritiesTable_019f8a30-86d1-76c3-8445-fbbaf5339768" xlink:to="loc_noc_InvestmentInPublicCompanyAxis_019f8a30-86d1-7694-a713-bc0bbb954564" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_InvestmentInPublicCompanyDomain_019f8a30-86d1-7694-a713-bc0bbb954564_default" xlink:href="noc-20260930.xsd#noc_InvestmentInPublicCompanyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_noc_InvestmentInPublicCompanyAxis_019f8a30-86d1-7694-a713-bc0bbb954564" xlink:to="loc_noc_InvestmentInPublicCompanyDomain_019f8a30-86d1-7694-a713-bc0bbb954564_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_InvestmentInPublicCompanyDomain_019f8a30-86d1-7d5d-8560-5ce3da950e4c" xlink:href="noc-20260930.xsd#noc_InvestmentInPublicCompanyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_noc_InvestmentInPublicCompanyAxis_019f8a30-86d1-7694-a713-bc0bbb954564" xlink:to="loc_noc_InvestmentInPublicCompanyDomain_019f8a30-86d1-7d5d-8560-5ce3da950e4c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_InvestmentInPublicCompanyMember_019f8a30-86d1-7eec-8468-44251fe9bafd" xlink:href="noc-20260930.xsd#noc_InvestmentInPublicCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_noc_InvestmentInPublicCompanyDomain_019f8a30-86d1-7d5d-8560-5ce3da950e4c" xlink:to="loc_noc_InvestmentInPublicCompanyMember_019f8a30-86d1-7eec-8468-44251fe9bafd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3_019f8a30-86d1-781e-a2ff-fd8e78f7bab3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019f8a30-86d1-7f4b-92e1-771fbde77c0f" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3_019f8a30-86d1-781e-a2ff-fd8e78f7bab3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiCurrentAndNoncurrent_019f8a30-86d1-716b-a94c-47a059d7f471" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecuritiesFvNiCurrentAndNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019f8a30-86d1-7f4b-92e1-771fbde77c0f" xlink:to="loc_us-gaap_EquitySecuritiesFvNiCurrentAndNoncurrent_019f8a30-86d1-716b-a94c-47a059d7f471" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecurityFvNiContractualSaleRestrictionNatureOfRestrictionAndCircumstanceForLapse_019f8a30-86d1-78b1-8c62-fa737c0db240" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquitySecurityFvNiContractualSaleRestrictionNatureOfRestrictionAndCircumstanceForLapse"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019f8a30-86d1-7f4b-92e1-771fbde77c0f" xlink:to="loc_us-gaap_EquitySecurityFvNiContractualSaleRestrictionNatureOfRestrictionAndCircumstanceForLapse_019f8a30-86d1-78b1-8c62-fa737c0db240" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketableSecuritiesUnrealizedGainLoss_019f8a30-86d1-72b5-b4ba-cc64d70e1523" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MarketableSecuritiesUnrealizedGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019f8a30-86d1-7f4b-92e1-771fbde77c0f" xlink:to="loc_us-gaap_MarketableSecuritiesUnrealizedGainLoss_019f8a30-86d1-72b5-b4ba-cc64d70e1523" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainOnSaleOfInvestments_019f8a30-86d1-7717-bb5c-52f25f68beb9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainOnSaleOfInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MarketableSecuritiesLineItems_019f8a30-86d1-7f4b-92e1-771fbde77c0f" xlink:to="loc_us-gaap_GainOnSaleOfInvestments_019f8a30-86d1-7717-bb5c-52f25f68beb9" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/FairValueofFinancialInstrumentsUnauditedLongtermDebtDetails3" xlink:type="simple" xlink:href="noc-20260930.xsd#FairValueofFinancialInstrumentsUnauditedLongtermDebtDetails3"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/FairValueofFinancialInstrumentsUnauditedLongtermDebtDetails3" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019f8a30-86d1-7e3a-87dc-1f5da56648c0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_019f8a30-86d1-724b-bdc6-24dc0759ecea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8a30-86d1-7e3a-87dc-1f5da56648c0" xlink:to="loc_us-gaap_DebtInstrumentTable_019f8a30-86d1-724b-bdc6-24dc0759ecea" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019f8a30-86d1-7580-8a21-da7da12fc59d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019f8a30-86d1-724b-bdc6-24dc0759ecea" xlink:to="loc_us-gaap_DebtInstrumentAxis_019f8a30-86d1-7580-8a21-da7da12fc59d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019f8a30-86d1-7580-8a21-da7da12fc59d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019f8a30-86d1-7580-8a21-da7da12fc59d" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019f8a30-86d1-7580-8a21-da7da12fc59d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019f8a30-86d1-7da7-b8ad-88dc949f6c0e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019f8a30-86d1-7580-8a21-da7da12fc59d" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019f8a30-86d1-7da7-b8ad-88dc949f6c0e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_A2025NotesMember_019f8a30-86d1-769d-b3de-eb922c864604" xlink:href="noc-20260930.xsd#noc_A2025NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8a30-86d1-7da7-b8ad-88dc949f6c0e" xlink:to="loc_noc_A2025NotesMember_019f8a30-86d1-769d-b3de-eb922c864604" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_A2030NotesMember_019f8a30-86d1-79a3-986c-b2814847d847" xlink:href="noc-20260930.xsd#noc_A2030NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8a30-86d1-7da7-b8ad-88dc949f6c0e" xlink:to="loc_noc_A2030NotesMember_019f8a30-86d1-79a3-986c-b2814847d847" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_A2035NotesMember_019f8a30-86d1-7cd4-9d26-3b0f9b4fdda2" xlink:href="noc-20260930.xsd#noc_A2035NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8a30-86d1-7da7-b8ad-88dc949f6c0e" xlink:to="loc_noc_A2035NotesMember_019f8a30-86d1-7cd4-9d26-3b0f9b4fdda2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_A2026Notes7.875Member_019f8a30-86d1-7552-9033-d199fa5b8e77" xlink:href="noc-20260930.xsd#noc_A2026Notes7.875Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8a30-86d1-7da7-b8ad-88dc949f6c0e" xlink:to="loc_noc_A2026Notes7.875Member_019f8a30-86d1-7552-9033-d199fa5b8e77" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_A2026Notes7.75Member_019f8a30-86d1-7ff3-affb-cb07bae2646c" xlink:href="noc-20260930.xsd#noc_A2026Notes7.75Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8a30-86d1-7da7-b8ad-88dc949f6c0e" xlink:to="loc_noc_A2026Notes7.75Member_019f8a30-86d1-7ff3-affb-cb07bae2646c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019f8a30-86d1-7187-bc93-74af912a2907" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8a30-86d1-7e3a-87dc-1f5da56648c0" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019f8a30-86d1-7187-bc93-74af912a2907" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019f8a30-86d1-7d6b-981c-9abc3799487f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8a30-86d1-7e3a-87dc-1f5da56648c0" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019f8a30-86d1-7d6b-981c-9abc3799487f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExtinguishmentOfDebtAmount_019f8a30-86d1-7d36-9bf5-2bdef725d8bd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ExtinguishmentOfDebtAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8a30-86d1-7e3a-87dc-1f5da56648c0" xlink:to="loc_us-gaap_ExtinguishmentOfDebtAmount_019f8a30-86d1-7d36-9bf5-2bdef725d8bd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentIssuedPrincipal_019f8a30-86d1-75f0-9d60-60c4348938c9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentIssuedPrincipal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019f8a30-86d1-7e3a-87dc-1f5da56648c0" xlink:to="loc_us-gaap_DebtInstrumentIssuedPrincipal_019f8a30-86d1-75f0-9d60-60c4348938c9" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/CommitmentsandContingenciesUnauditedDetails" xlink:type="simple" xlink:href="noc-20260930.xsd#CommitmentsandContingenciesUnauditedDetails"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/CommitmentsandContingenciesUnauditedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_019f8a30-86d1-7a1c-82bb-b5c35b773494" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_019f8a30-86d1-7338-80a6-3887370a71e9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_019f8a30-86d1-7a1c-82bb-b5c35b773494" xlink:to="loc_us-gaap_LossContingenciesTable_019f8a30-86d1-7338-80a6-3887370a71e9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_019f8a30-86d1-7606-a5d7-e786cafae124" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019f8a30-86d1-7338-80a6-3887370a71e9" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_019f8a30-86d1-7606-a5d7-e786cafae124" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_019f8a30-86d1-7606-a5d7-e786cafae124_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_019f8a30-86d1-7606-a5d7-e786cafae124" xlink:to="loc_us-gaap_LossContingencyNatureDomain_019f8a30-86d1-7606-a5d7-e786cafae124_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_019f8a30-86d1-78ce-b50f-b2447245c8ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_019f8a30-86d1-7606-a5d7-e786cafae124" xlink:to="loc_us-gaap_LossContingencyNatureDomain_019f8a30-86d1-78ce-b50f-b2447245c8ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_MinimumLossContingencyMember_019f8a30-86d1-71b8-a5a8-616ecb72ecdf" xlink:href="noc-20260930.xsd#noc_MinimumLossContingencyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_019f8a30-86d1-78ce-b50f-b2447245c8ce" xlink:to="loc_noc_MinimumLossContingencyMember_019f8a30-86d1-71b8-a5a8-616ecb72ecdf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_MaximumLossContingencyMember_019f8a30-86d1-7728-892e-80e5751e912c" xlink:href="noc-20260930.xsd#noc_MaximumLossContingencyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_019f8a30-86d1-78ce-b50f-b2447245c8ce" xlink:to="loc_noc_MaximumLossContingencyMember_019f8a30-86d1-7728-892e-80e5751e912c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_019f8a30-86d1-787b-ae76-57e0afddf051" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019f8a30-86d1-7338-80a6-3887370a71e9" xlink:to="loc_srt_MajorCustomersAxis_019f8a30-86d1-787b-ae76-57e0afddf051" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_019f8a30-86d1-787b-ae76-57e0afddf051_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_019f8a30-86d1-787b-ae76-57e0afddf051" xlink:to="loc_srt_NameOfMajorCustomerDomain_019f8a30-86d1-787b-ae76-57e0afddf051_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_019f8a30-86d1-79e0-a8e1-f53fbe6b6986" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_019f8a30-86d1-787b-ae76-57e0afddf051" xlink:to="loc_srt_NameOfMajorCustomerDomain_019f8a30-86d1-79e0-a8e1-f53fbe6b6986" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyEstimateOfPossibleLoss_019f8a30-86d1-7791-8123-b2f9410f57bd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyEstimateOfPossibleLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019f8a30-86d1-7a1c-82bb-b5c35b773494" xlink:to="loc_us-gaap_LossContingencyEstimateOfPossibleLoss_019f8a30-86d1-7791-8123-b2f9410f57bd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SiteContingencyLineItems_019f8a30-86d1-7bef-a341-46e2ab836f85" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SiteContingencyLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SiteContingencyTable_019f8a30-86d1-7c25-9dcc-5fd9f14192e0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SiteContingencyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SiteContingencyLineItems_019f8a30-86d1-7bef-a341-46e2ab836f85" xlink:to="loc_us-gaap_SiteContingencyTable_019f8a30-86d1-7c25-9dcc-5fd9f14192e0" xlink:type="arc" order="2" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccrualForEnvironmentalLossContingencies_019f8a30-86d1-74ce-afdc-0427e7e7f178" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccrualForEnvironmentalLossContingencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019f8a30-86d1-7bef-a341-46e2ab836f85" xlink:to="loc_us-gaap_AccrualForEnvironmentalLossContingencies_019f8a30-86d1-74ce-afdc-0427e7e7f178" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RecordedThirdPartyEnvironmentalRecoveriesAmount_019f8a30-86d1-7b05-92c9-3c79cb29cc02" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RecordedThirdPartyEnvironmentalRecoveriesAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019f8a30-86d1-7bef-a341-46e2ab836f85" xlink:to="loc_us-gaap_RecordedThirdPartyEnvironmentalRecoveriesAmount_019f8a30-86d1-7b05-92c9-3c79cb29cc02" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedEnvironmentalLossContingenciesCurrent_019f8a30-86d1-72d7-bbb4-e38bf525216d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedEnvironmentalLossContingenciesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019f8a30-86d1-7bef-a341-46e2ab836f85" xlink:to="loc_us-gaap_AccruedEnvironmentalLossContingenciesCurrent_019f8a30-86d1-72d7-bbb4-e38bf525216d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedEnvironmentalLossContingenciesNoncurrent_019f8a30-86d1-7b03-99a5-a287958bf9a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedEnvironmentalLossContingenciesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019f8a30-86d1-7bef-a341-46e2ab836f85" xlink:to="loc_us-gaap_AccruedEnvironmentalLossContingenciesNoncurrent_019f8a30-86d1-7b03-99a5-a287958bf9a8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RecordedThirdPartyEnvironmentalRecoveriesCurrent_019f8a30-86d1-7d59-aa47-f25a641dd9f0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RecordedThirdPartyEnvironmentalRecoveriesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019f8a30-86d1-7bef-a341-46e2ab836f85" xlink:to="loc_us-gaap_RecordedThirdPartyEnvironmentalRecoveriesCurrent_019f8a30-86d1-7d59-aa47-f25a641dd9f0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RecordedThirdPartyEnvironmentalRecoveriesNoncurrent_019f8a30-86d1-774f-acd7-8c6055ed1f6f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RecordedThirdPartyEnvironmentalRecoveriesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019f8a30-86d1-7bef-a341-46e2ab836f85" xlink:to="loc_us-gaap_RecordedThirdPartyEnvironmentalRecoveriesNoncurrent_019f8a30-86d1-774f-acd7-8c6055ed1f6f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyRangeOfPossibleLossPortionNotAccrued_019f8a30-86d1-75eb-80ed-ed393d2d766f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingencyRangeOfPossibleLossPortionNotAccrued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019f8a30-86d1-7bef-a341-46e2ab836f85" xlink:to="loc_us-gaap_LossContingencyRangeOfPossibleLossPortionNotAccrued_019f8a30-86d1-75eb-80ed-ed393d2d766f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EnvironmentalCostsRecognizedRecoveryCreditedToExpense_019f8a30-86d1-7a5f-a711-7d522971af1f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EnvironmentalCostsRecognizedRecoveryCreditedToExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SiteContingencyLineItems_019f8a30-86d1-7bef-a341-46e2ab836f85" xlink:to="loc_us-gaap_EnvironmentalCostsRecognizedRecoveryCreditedToExpense_019f8a30-86d1-7a5f-a711-7d522971af1f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_019f8a30-86d1-7e9f-9060-d9e4c6e6c051" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityTable_019f8a30-86d1-7fc8-88dd-c78c003c58d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019f8a30-86d1-7e9f-9060-d9e4c6e6c051" xlink:to="loc_us-gaap_LineOfCreditFacilityTable_019f8a30-86d1-7fc8-88dd-c78c003c58d0" xlink:type="arc" order="3" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeAxis_019f8a30-86d1-7fb3-a20c-5ab953e014be" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_019f8a30-86d1-7fc8-88dd-c78c003c58d0" xlink:to="loc_us-gaap_ShortTermDebtTypeAxis_019f8a30-86d1-7fb3-a20c-5ab953e014be" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_019f8a30-86d1-7fb3-a20c-5ab953e014be_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_019f8a30-86d1-7fb3-a20c-5ab953e014be" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_019f8a30-86d1-7fb3-a20c-5ab953e014be_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_019f8a30-86d1-722f-80af-8b14927f8e03" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_019f8a30-86d1-7fb3-a20c-5ab953e014be" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_019f8a30-86d1-722f-80af-8b14927f8e03" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperMember_019f8a30-86d1-7667-9d32-acc4dc92e8b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialPaperMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermDebtTypeDomain_019f8a30-86d1-722f-80af-8b14927f8e03" xlink:to="loc_us-gaap_CommercialPaperMember_019f8a30-86d1-7667-9d32-acc4dc92e8b8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019f8a30-86d1-7178-8140-dcae3303a33f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_019f8a30-86d1-7fc8-88dd-c78c003c58d0" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019f8a30-86d1-7178-8140-dcae3303a33f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019f8a30-86d1-7178-8140-dcae3303a33f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019f8a30-86d1-7178-8140-dcae3303a33f" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019f8a30-86d1-7178-8140-dcae3303a33f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019f8a30-86d1-76a0-bd42-f5733c0bcf25" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019f8a30-86d1-7178-8140-dcae3303a33f" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019f8a30-86d1-76a0-bd42-f5733c0bcf25" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_019f8a30-86d1-743f-82ae-2f426f01f9a1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_019f8a30-86d1-7fc8-88dd-c78c003c58d0" xlink:to="loc_us-gaap_VariableRateAxis_019f8a30-86d1-743f-82ae-2f426f01f9a1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019f8a30-86d1-743f-82ae-2f426f01f9a1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_019f8a30-86d1-743f-82ae-2f426f01f9a1" xlink:to="loc_us-gaap_VariableRateDomain_019f8a30-86d1-743f-82ae-2f426f01f9a1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_019f8a30-86d1-74d1-8c82-ab5994481299" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_019f8a30-86d1-743f-82ae-2f426f01f9a1" xlink:to="loc_us-gaap_VariableRateDomain_019f8a30-86d1-74d1-8c82-ab5994481299" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019f8a30-86d1-7b12-bbae-de0b0ee78995" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_019f8a30-86d1-7fc8-88dd-c78c003c58d0" xlink:to="loc_us-gaap_CreditFacilityAxis_019f8a30-86d1-7b12-bbae-de0b0ee78995" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019f8a30-86d1-7b12-bbae-de0b0ee78995_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019f8a30-86d1-7b12-bbae-de0b0ee78995" xlink:to="loc_us-gaap_CreditFacilityDomain_019f8a30-86d1-7b12-bbae-de0b0ee78995_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019f8a30-86d1-7f73-b9b6-dfd86dbed5b7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019f8a30-86d1-7b12-bbae-de0b0ee78995" xlink:to="loc_us-gaap_CreditFacilityDomain_019f8a30-86d1-7f73-b9b6-dfd86dbed5b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019f8a30-86d1-7262-bee1-255d663ed715" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LineOfCreditFacilityTable_019f8a30-86d1-7fc8-88dd-c78c003c58d0" xlink:to="loc_us-gaap_DebtInstrumentAxis_019f8a30-86d1-7262-bee1-255d663ed715" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019f8a30-86d1-7262-bee1-255d663ed715_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019f8a30-86d1-7262-bee1-255d663ed715" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019f8a30-86d1-7262-bee1-255d663ed715_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019f8a30-86d1-7b45-b7f8-5c814dcc3327" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019f8a30-86d1-7262-bee1-255d663ed715" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019f8a30-86d1-7b45-b7f8-5c814dcc3327" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_A2025FiveYearTermMember_019f8a30-86d1-7eee-8a8a-2cc39f376efd" xlink:href="noc-20260930.xsd#noc_A2025FiveYearTermMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019f8a30-86d1-7b45-b7f8-5c814dcc3327" xlink:to="loc_noc_A2025FiveYearTermMember_019f8a30-86d1-7eee-8a8a-2cc39f376efd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_CommercialPaperMaximumBorrowingCapacityPrior_019f8a30-86d1-7711-a2d2-75356dded71d" xlink:href="noc-20260930.xsd#noc_CommercialPaperMaximumBorrowingCapacityPrior"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019f8a30-86d1-7e9f-9060-d9e4c6e6c051" xlink:to="loc_noc_CommercialPaperMaximumBorrowingCapacityPrior_019f8a30-86d1-7711-a2d2-75356dded71d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_CommercialPaperMaximumBorrowingCapacity_019f8a30-86d1-7fe4-9844-a0b239aba2e4" xlink:href="noc-20260930.xsd#noc_CommercialPaperMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019f8a30-86d1-7e9f-9060-d9e4c6e6c051" xlink:to="loc_noc_CommercialPaperMaximumBorrowingCapacity_019f8a30-86d1-7fe4-9844-a0b239aba2e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperAtCarryingValue_019f8a30-86d1-7efc-9126-b44c4ede64cf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialPaperAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019f8a30-86d1-7e9f-9060-d9e4c6e6c051" xlink:to="loc_us-gaap_CommercialPaperAtCarryingValue_019f8a30-86d1-7efc-9126-b44c4ede64cf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaper_019f8a30-86d1-76fb-9bd5-3469fcd83cd6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialPaper"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019f8a30-86d1-7e9f-9060-d9e4c6e6c051" xlink:to="loc_us-gaap_CommercialPaper_019f8a30-86d1-76fb-9bd5-3469fcd83cd6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CommercialPaperAverageRatePaid_019f8a30-86d1-7bc4-994e-ca5c433d21e6" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_CommercialPaperAverageRatePaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019f8a30-86d1-7e9f-9060-d9e4c6e6c051" xlink:to="loc_srt_CommercialPaperAverageRatePaid_019f8a30-86d1-7bc4-994e-ca5c433d21e6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019f8a30-86d1-7c89-9f4d-081f58d41d82" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019f8a30-86d1-7e9f-9060-d9e4c6e6c051" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019f8a30-86d1-7c89-9f4d-081f58d41d82" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_019f8a30-86d1-76ae-95a4-62c437498381" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019f8a30-86d1-7e9f-9060-d9e4c6e6c051" xlink:to="loc_us-gaap_LineOfCredit_019f8a30-86d1-76ae-95a4-62c437498381" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCovenantCompliance_019f8a30-86d1-7750-9601-c512a8dc79be" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentCovenantCompliance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019f8a30-86d1-7e9f-9060-d9e4c6e6c051" xlink:to="loc_us-gaap_DebtInstrumentCovenantCompliance_019f8a30-86d1-7750-9601-c512a8dc79be" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCovenantCompliance_019f8a30-86d1-71a6-9e76-bb71205f7e25" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityCovenantCompliance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019f8a30-86d1-7e9f-9060-d9e4c6e6c051" xlink:to="loc_us-gaap_LineOfCreditFacilityCovenantCompliance_019f8a30-86d1-71a6-9e76-bb71205f7e25" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCovenantTerms_019f8a30-86d1-7e40-af8a-371c3d833f5f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityCovenantTerms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLineItems_019f8a30-86d1-7e9f-9060-d9e4c6e6c051" xlink:to="loc_us-gaap_LineOfCreditFacilityCovenantTerms_019f8a30-86d1-7e40-af8a-371c3d833f5f" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLineItems_019f8a30-86d1-7d11-8d89-f8bc80cbb820" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityTable_019f8a30-86d1-76f3-abb4-85131f4ac8c8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityTable"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeAxis_019f8a30-86d1-7c12-bfe3-dcb71ee72e23" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermDebtTypeAxis"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_019f8a30-86d1-7c12-bfe3-dcb71ee72e23_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_019f8a30-86d1-782d-8a1c-94781776d45c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperMember_019f8a30-86d1-7253-819e-25d535966f23" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialPaperMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019f8a30-86d1-7e6e-b00d-2969fe9a5845" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019f8a30-86d1-7e6e-b00d-2969fe9a5845_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019f8a30-86d1-74cc-9ee1-7d28f13d43e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_A2025FiveYearTermMember_019f8a30-86d1-7b4b-bbcb-95b55624a339" xlink:href="noc-20260930.xsd#noc_A2025FiveYearTermMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperAtCarryingValue_019f8a30-86d1-71f4-a469-65a3371e85e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialPaperAtCarryingValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_019f8a30-86d1-7b85-ad71-47a37d770e1e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCredit"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/RetirementBenefitsUnauditedDetails" xlink:type="simple" xlink:href="noc-20260930.xsd#RetirementBenefitsUnauditedDetails"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/RetirementBenefitsUnauditedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019f8a30-86d1-7fa3-9530-7528f27f2469" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_019f8a30-86d1-7ee7-bd14-9fd7518c49ad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019f8a30-86d1-7fa3-9530-7528f27f2469" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_019f8a30-86d1-7ee7-bd14-9fd7518c49ad" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_019f8a30-86d1-7dba-ba3f-9d7d71f74008" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_019f8a30-86d1-7ee7-bd14-9fd7518c49ad" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_019f8a30-86d1-7dba-ba3f-9d7d71f74008" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_019f8a30-86d1-7dba-ba3f-9d7d71f74008_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_019f8a30-86d1-7dba-ba3f-9d7d71f74008" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_019f8a30-86d1-7dba-ba3f-9d7d71f74008_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_019f8a30-86d1-73e4-b1ac-0a4ea7810970" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_019f8a30-86d1-7dba-ba3f-9d7d71f74008" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_019f8a30-86d1-73e4-b1ac-0a4ea7810970" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_019f8a30-86d1-71a1-9b08-43743a0b1d33" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_019f8a30-86d1-73e4-b1ac-0a4ea7810970" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_019f8a30-86d1-71a1-9b08-43743a0b1d33" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_019f8a30-86d1-7101-94df-a7db0ca9748b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_019f8a30-86d1-73e4-b1ac-0a4ea7810970" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_019f8a30-86d1-7101-94df-a7db0ca9748b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_019f8a30-86d1-7482-bf03-eb481d839386" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019f8a30-86d1-7fa3-9530-7528f27f2469" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_019f8a30-86d1-7482-bf03-eb481d839386" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_019f8a30-86d1-712b-b9da-f99b8fd31b12" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanServiceCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_019f8a30-86d1-7482-bf03-eb481d839386" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_019f8a30-86d1-712b-b9da-f99b8fd31b12" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_019f8a30-86d1-7a48-b636-3179d8697270" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanInterestCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_019f8a30-86d1-7482-bf03-eb481d839386" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_019f8a30-86d1-7a48-b636-3179d8697270" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_019f8a30-86d1-7e1f-8217-ee3b29da9c5c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_019f8a30-86d1-7482-bf03-eb481d839386" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_019f8a30-86d1-7e1f-8217-ee3b29da9c5c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_019f8a30-86d1-7f5c-8163-73ba6df8c172" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_019f8a30-86d1-7482-bf03-eb481d839386" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_019f8a30-86d1-7f5c-8163-73ba6df8c172" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanOtherCosts_019f8a30-86d1-7654-9839-aced52a2d9eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanOtherCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_019f8a30-86d1-7482-bf03-eb481d839386" xlink:to="loc_us-gaap_DefinedBenefitPlanOtherCosts_019f8a30-86d1-7654-9839-aced52a2d9eb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_019f8a30-86d1-774a-ab6b-cee1875578cd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostAbstract_019f8a30-86d1-7482-bf03-eb481d839386" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_019f8a30-86d1-774a-ab6b-cee1875578cd" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_019f8a30-86d1-7bcd-87bc-8ebe1be44c54" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanContributionsByEmployer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019f8a30-86d1-7fa3-9530-7528f27f2469" xlink:to="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_019f8a30-86d1-7bcd-87bc-8ebe1be44c54" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount_019f8a30-86d1-7468-990d-b5b58b7fd235" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019f8a30-86d1-7fa3-9530-7528f27f2469" xlink:to="loc_us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount_019f8a30-86d1-7468-990d-b5b58b7fd235" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/StockCompensationPlansandOtherCompensationArrangementsUnauditedDetails" xlink:type="simple" xlink:href="noc-20260930.xsd#StockCompensationPlansandOtherCompensationArrangementsUnauditedDetails"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/StockCompensationPlansandOtherCompensationArrangementsUnauditedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8a30-86d1-7b32-9075-feebb3db2f45" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f8a30-86d1-75dc-9221-de7122ccb2d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8a30-86d1-7b32-9075-feebb3db2f45" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f8a30-86d1-75dc-9221-de7122ccb2d7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019f8a30-86d1-7881-990c-5f2a4d574cf1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f8a30-86d1-75dc-9221-de7122ccb2d7" xlink:to="loc_us-gaap_AwardTypeAxis_019f8a30-86d1-7881-990c-5f2a4d574cf1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8a30-86d1-7881-990c-5f2a4d574cf1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019f8a30-86d1-7881-990c-5f2a4d574cf1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8a30-86d1-7881-990c-5f2a4d574cf1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8a30-86d1-71f7-8a64-c7e9a9f79499" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019f8a30-86d1-7881-990c-5f2a4d574cf1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8a30-86d1-71f7-8a64-c7e9a9f79499" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019f8a30-86d1-747c-b952-b48a07865f99" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8a30-86d1-71f7-8a64-c7e9a9f79499" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019f8a30-86d1-747c-b952-b48a07865f99" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_019f8a30-86d1-7f20-b5e8-f5892c32bd23" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8a30-86d1-71f7-8a64-c7e9a9f79499" xlink:to="loc_us-gaap_PerformanceSharesMember_019f8a30-86d1-7f20-b5e8-f5892c32bd23" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_CashUnitsAndCashPerformanceUnitsMember_019f8a30-86d1-708e-9345-ae35dc419b5d" xlink:href="noc-20260930.xsd#noc_CashUnitsAndCashPerformanceUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8a30-86d1-71f7-8a64-c7e9a9f79499" xlink:to="loc_noc_CashUnitsAndCashPerformanceUnitsMember_019f8a30-86d1-708e-9345-ae35dc419b5d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_CashPerformanceUnitsMember_019f8a30-86d1-7f76-8d57-5f15c724a801" xlink:href="noc-20260930.xsd#noc_CashPerformanceUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f8a30-86d1-71f7-8a64-c7e9a9f79499" xlink:to="loc_noc_CashPerformanceUnitsMember_019f8a30-86d1-7f76-8d57-5f15c724a801" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019f8a30-86d1-7bb5-8380-5d23f24a079c" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f8a30-86d1-75dc-9221-de7122ccb2d7" xlink:to="loc_srt_RangeAxis_019f8a30-86d1-7bb5-8380-5d23f24a079c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f8a30-86d1-7bb5-8380-5d23f24a079c_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_019f8a30-86d1-7bb5-8380-5d23f24a079c" xlink:to="loc_srt_RangeMember_019f8a30-86d1-7bb5-8380-5d23f24a079c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f8a30-86d1-792c-a820-d3d085ce95e9" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_019f8a30-86d1-7bb5-8380-5d23f24a079c" xlink:to="loc_srt_RangeMember_019f8a30-86d1-792c-a820-d3d085ce95e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019f8a30-86d1-7a33-84f0-7441fa321353" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019f8a30-86d1-792c-a820-d3d085ce95e9" xlink:to="loc_srt_MinimumMember_019f8a30-86d1-7a33-84f0-7441fa321353" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019f8a30-86d1-776b-aead-3301d9964cf0" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_019f8a30-86d1-792c-a820-d3d085ce95e9" xlink:to="loc_srt_MaximumMember_019f8a30-86d1-776b-aead-3301d9964cf0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019f8a30-86d1-70f0-9de1-ace0ec75a28b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8a30-86d1-7b32-9075-feebb3db2f45" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019f8a30-86d1-70f0-9de1-ace0ec75a28b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_RestrictedStockRightsRestrictedPerformanceStockRightsAndMarketStockUnitsGrantDateAggregateFairValue_019f8a30-86d1-7c5e-96fa-ab25e3022bb9" xlink:href="noc-20260930.xsd#noc_RestrictedStockRightsRestrictedPerformanceStockRightsAndMarketStockUnitsGrantDateAggregateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8a30-86d1-7b32-9075-feebb3db2f45" xlink:to="loc_noc_RestrictedStockRightsRestrictedPerformanceStockRightsAndMarketStockUnitsGrantDateAggregateFairValue_019f8a30-86d1-7c5e-96fa-ab25e3022bb9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredCompensationCashbasedArrangementsLiabilityCurrentAndNoncurrent_019f8a30-86d1-77d9-a006-de22410e4e66" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredCompensationCashbasedArrangementsLiabilityCurrentAndNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8a30-86d1-7b32-9075-feebb3db2f45" xlink:to="loc_us-gaap_DeferredCompensationCashbasedArrangementsLiabilityCurrentAndNoncurrent_019f8a30-86d1-77d9-a006-de22410e4e66" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019f8a30-86d1-793b-8af3-d23420b8a4f3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f8a30-86d1-7b32-9075-feebb3db2f45" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_019f8a30-86d1-793b-8af3-d23420b8a4f3" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/SegmentInformationUnauditedReconciliationtoConsolidatedOperatingIncomeDetails1" xlink:type="simple" xlink:href="noc-20260930.xsd#SegmentInformationUnauditedReconciliationtoConsolidatedOperatingIncomeDetails1"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/SegmentInformationUnauditedReconciliationtoConsolidatedOperatingIncomeDetails1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019f8a30-86d1-7e33-bca7-12b3fee22840" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8a30-86d1-7dca-bd05-df2e70695536" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8a30-86d1-7e33-bca7-12b3fee22840" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8a30-86d1-7dca-bd05-df2e70695536" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019f8a30-86d1-7822-8aa1-843c47959e38" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8a30-86d1-7dca-bd05-df2e70695536" xlink:to="loc_srt_ConsolidationItemsAxis_019f8a30-86d1-7822-8aa1-843c47959e38" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019f8a30-86d1-7822-8aa1-843c47959e38_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019f8a30-86d1-7822-8aa1-843c47959e38" xlink:to="loc_srt_ConsolidationItemsDomain_019f8a30-86d1-7822-8aa1-843c47959e38_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019f8a30-86d1-751a-ae10-edb85add254e" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019f8a30-86d1-7822-8aa1-843c47959e38" xlink:to="loc_srt_ConsolidationItemsDomain_019f8a30-86d1-751a-ae10-edb85add254e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019f8a30-86d1-76e8-95da-f98d3852ac18" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019f8a30-86d1-751a-ae10-edb85add254e" xlink:to="loc_us-gaap_OperatingSegmentsMember_019f8a30-86d1-76e8-95da-f98d3852ac18" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_019f8a30-86d1-7e18-8416-0aff654921f0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntersegmentEliminationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019f8a30-86d1-751a-ae10-edb85add254e" xlink:to="loc_us-gaap_IntersegmentEliminationMember_019f8a30-86d1-7e18-8416-0aff654921f0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MaterialReconcilingItemsMember_019f8a30-86d1-77d5-9430-9139cc057dd7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MaterialReconcilingItemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019f8a30-86d1-751a-ae10-edb85add254e" xlink:to="loc_us-gaap_MaterialReconcilingItemsMember_019f8a30-86d1-77d5-9430-9139cc057dd7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d1-7a5d-803d-f5512df22cdb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8a30-86d1-7dca-bd05-df2e70695536" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d1-7a5d-803d-f5512df22cdb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8a30-86d1-7a5d-803d-f5512df22cdb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d1-7a5d-803d-f5512df22cdb" xlink:to="loc_us-gaap_SegmentDomain_019f8a30-86d1-7a5d-803d-f5512df22cdb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8a30-86d1-7ba3-a2c5-598b6ece4ad0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d1-7a5d-803d-f5512df22cdb" xlink:to="loc_us-gaap_SegmentDomain_019f8a30-86d1-7ba3-a2c5-598b6ece4ad0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_AeronauticsSystemsMember_019f8a30-86d1-7c28-820e-9b4a6bc30310" xlink:href="noc-20260930.xsd#noc_AeronauticsSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d1-7ba3-a2c5-598b6ece4ad0" xlink:to="loc_noc_AeronauticsSystemsMember_019f8a30-86d1-7c28-820e-9b4a6bc30310" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_DefenseSystemsMember_019f8a30-86d1-7948-ae50-e536f7fc6f49" xlink:href="noc-20260930.xsd#noc_DefenseSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d1-7ba3-a2c5-598b6ece4ad0" xlink:to="loc_noc_DefenseSystemsMember_019f8a30-86d1-7948-ae50-e536f7fc6f49" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_MissionSystemsMember_019f8a30-86d1-7fe4-9bc8-c66a301a3acb" xlink:href="noc-20260930.xsd#noc_MissionSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d1-7ba3-a2c5-598b6ece4ad0" xlink:to="loc_noc_MissionSystemsMember_019f8a30-86d1-7fe4-9bc8-c66a301a3acb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_SpaceSystemsMember_019f8a30-86d1-73ae-bee0-bac67186bcf1" xlink:href="noc-20260930.xsd#noc_SpaceSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d1-7ba3-a2c5-598b6ece4ad0" xlink:to="loc_noc_SpaceSystemsMember_019f8a30-86d1-73ae-bee0-bac67186bcf1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019f8a30-86d1-7697-967d-188bc6be10f6" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8a30-86d1-7dca-bd05-df2e70695536" xlink:to="loc_srt_ProductOrServiceAxis_019f8a30-86d1-7697-967d-188bc6be10f6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f8a30-86d1-7697-967d-188bc6be10f6_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019f8a30-86d1-7697-967d-188bc6be10f6" xlink:to="loc_srt_ProductsAndServicesDomain_019f8a30-86d1-7697-967d-188bc6be10f6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f8a30-86d1-70be-aeeb-dae100e49cb1" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019f8a30-86d1-7697-967d-188bc6be10f6" xlink:to="loc_srt_ProductsAndServicesDomain_019f8a30-86d1-70be-aeeb-dae100e49cb1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductMember_019f8a30-86d1-7aed-b159-955cb9bf1c4b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProductMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8a30-86d1-70be-aeeb-dae100e49cb1" xlink:to="loc_us-gaap_ProductMember_019f8a30-86d1-7aed-b159-955cb9bf1c4b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_019f8a30-86d1-74d0-abd1-b7934a33c021" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8a30-86d1-70be-aeeb-dae100e49cb1" xlink:to="loc_us-gaap_ServiceMember_019f8a30-86d1-74d0-abd1-b7934a33c021" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_IntersegmentCostsMember_019f8a30-86d1-7790-b503-dfe59f937945" xlink:href="noc-20260930.xsd#noc_IntersegmentCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f8a30-86d1-70be-aeeb-dae100e49cb1" xlink:to="loc_noc_IntersegmentCostsMember_019f8a30-86d1-7790-b503-dfe59f937945" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationRevenueAbstract_019f8a30-86d1-74a2-aeae-0919580e812b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationRevenueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8a30-86d1-7e33-bca7-12b3fee22840" xlink:to="loc_us-gaap_SegmentReportingInformationRevenueAbstract_019f8a30-86d1-74a2-aeae-0919580e812b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019f8a30-86d1-78f7-8740-fd3156376b44" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationRevenueAbstract_019f8a30-86d1-74a2-aeae-0919580e812b" xlink:to="loc_us-gaap_Revenues_019f8a30-86d1-78f7-8740-fd3156376b44" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_019f8a30-86d1-7475-a7a5-66abac42cb13" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationRevenueAbstract_019f8a30-86d1-74a2-aeae-0919580e812b" xlink:to="loc_us-gaap_OperatingExpenses_019f8a30-86d1-7475-a7a5-66abac42cb13" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_FASCASOperatingAdjustment_019f8a30-86d1-7a61-8160-45b2ee032000" xlink:href="noc-20260930.xsd#noc_FASCASOperatingAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationRevenueAbstract_019f8a30-86d1-74a2-aeae-0919580e812b" xlink:to="loc_noc_FASCASOperatingAdjustment_019f8a30-86d1-7a61-8160-45b2ee032000" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019f8a30-86d1-792d-8dd6-d5008bf3e059" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationRevenueAbstract_019f8a30-86d1-74a2-aeae-0919580e812b" xlink:to="loc_us-gaap_OperatingIncomeLoss_019f8a30-86d1-792d-8dd6-d5008bf3e059" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDebtExpense_019f8a30-86d1-7f88-9072-978747b51897" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestAndDebtExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationRevenueAbstract_019f8a30-86d1-74a2-aeae-0919580e812b" xlink:to="loc_us-gaap_InterestAndDebtExpense_019f8a30-86d1-7f88-9072-978747b51897" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_NonOperatingFASPensionBenefit_019f8a30-86d1-7b64-8d64-1609537fddb2" xlink:href="noc-20260930.xsd#noc_NonOperatingFASPensionBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationRevenueAbstract_019f8a30-86d1-74a2-aeae-0919580e812b" xlink:to="loc_noc_NonOperatingFASPensionBenefit_019f8a30-86d1-7b64-8d64-1609537fddb2" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019f8a30-86d1-7fa6-92e6-9fed8a0e15b2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationRevenueAbstract_019f8a30-86d1-74a2-aeae-0919580e812b" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019f8a30-86d1-7fa6-92e6-9fed8a0e15b2" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019f8a30-86d1-76cd-9d4c-c6f6ced9c338" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationRevenueAbstract_019f8a30-86d1-74a2-aeae-0919580e812b" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019f8a30-86d1-76cd-9d4c-c6f6ced9c338" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfBusiness_019f8a30-86d1-799d-8078-daa40aafbbb9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnSaleOfBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationRevenueAbstract_019f8a30-86d1-74a2-aeae-0919580e812b" xlink:to="loc_us-gaap_GainLossOnSaleOfBusiness_019f8a30-86d1-799d-8078-daa40aafbbb9" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_UnallowableStateTaxesAndTransactionsCostsFromDivestiture_019f8a30-86d1-7634-bb5a-c5aa3c453c3b" xlink:href="noc-20260930.xsd#noc_UnallowableStateTaxesAndTransactionsCostsFromDivestiture"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationRevenueAbstract_019f8a30-86d1-74a2-aeae-0919580e812b" xlink:to="loc_noc_UnallowableStateTaxesAndTransactionsCostsFromDivestiture_019f8a30-86d1-7634-bb5a-c5aa3c453c3b" xlink:type="arc" order="10"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/SegmentInformationUnauditedSalesbyCustomerTypeDetails2" xlink:type="simple" xlink:href="noc-20260930.xsd#SegmentInformationUnauditedSalesbyCustomerTypeDetails2"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/SegmentInformationUnauditedSalesbyCustomerTypeDetails2" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_019f8a30-86d1-79e1-8fef-0a3816f0c583" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EntityWideRevenueMajorCustomerLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_019f8a30-86d1-7a66-9e3d-e0573598fadc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_019f8a30-86d1-79e1-8fef-0a3816f0c583" xlink:to="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_019f8a30-86d1-7a66-9e3d-e0573598fadc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d1-70f1-bb10-325d70c96dad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_019f8a30-86d1-7a66-9e3d-e0573598fadc" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d1-70f1-bb10-325d70c96dad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8a30-86d1-70f1-bb10-325d70c96dad_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d1-70f1-bb10-325d70c96dad" xlink:to="loc_us-gaap_SegmentDomain_019f8a30-86d1-70f1-bb10-325d70c96dad_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8a30-86d1-7e2f-ad05-554a0ce2e356" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d1-70f1-bb10-325d70c96dad" xlink:to="loc_us-gaap_SegmentDomain_019f8a30-86d1-7e2f-ad05-554a0ce2e356" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_AeronauticsSystemsMember_019f8a30-86d1-71b8-910b-d4cef114e178" xlink:href="noc-20260930.xsd#noc_AeronauticsSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d1-7e2f-ad05-554a0ce2e356" xlink:to="loc_noc_AeronauticsSystemsMember_019f8a30-86d1-71b8-910b-d4cef114e178" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_DefenseSystemsMember_019f8a30-86d1-7b35-bd11-62456fa050ed" xlink:href="noc-20260930.xsd#noc_DefenseSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d1-7e2f-ad05-554a0ce2e356" xlink:to="loc_noc_DefenseSystemsMember_019f8a30-86d1-7b35-bd11-62456fa050ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_MissionSystemsMember_019f8a30-86d1-7f5a-a27b-039c31b6a395" xlink:href="noc-20260930.xsd#noc_MissionSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d1-7e2f-ad05-554a0ce2e356" xlink:to="loc_noc_MissionSystemsMember_019f8a30-86d1-7f5a-a27b-039c31b6a395" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_SpaceSystemsMember_019f8a30-86d1-766d-8f63-b86aa5f946f0" xlink:href="noc-20260930.xsd#noc_SpaceSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d1-7e2f-ad05-554a0ce2e356" xlink:to="loc_noc_SpaceSystemsMember_019f8a30-86d1-766d-8f63-b86aa5f946f0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019f8a30-86d1-7a89-a676-6059c998974f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_019f8a30-86d1-7a66-9e3d-e0573598fadc" xlink:to="loc_srt_ConsolidationItemsAxis_019f8a30-86d1-7a89-a676-6059c998974f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019f8a30-86d1-7a89-a676-6059c998974f_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019f8a30-86d1-7a89-a676-6059c998974f" xlink:to="loc_srt_ConsolidationItemsDomain_019f8a30-86d1-7a89-a676-6059c998974f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019f8a30-86d1-731c-8bdb-15fa1cc8cedb" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019f8a30-86d1-7a89-a676-6059c998974f" xlink:to="loc_srt_ConsolidationItemsDomain_019f8a30-86d1-731c-8bdb-15fa1cc8cedb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019f8a30-86d1-7e10-a185-76a9627ede78" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019f8a30-86d1-731c-8bdb-15fa1cc8cedb" xlink:to="loc_us-gaap_OperatingSegmentsMember_019f8a30-86d1-7e10-a185-76a9627ede78" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_019f8a30-86d1-70ee-bf59-701ee128e4d5" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_019f8a30-86d1-7a66-9e3d-e0573598fadc" xlink:to="loc_srt_MajorCustomersAxis_019f8a30-86d1-70ee-bf59-701ee128e4d5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_019f8a30-86d1-70ee-bf59-701ee128e4d5_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_019f8a30-86d1-70ee-bf59-701ee128e4d5" xlink:to="loc_srt_NameOfMajorCustomerDomain_019f8a30-86d1-70ee-bf59-701ee128e4d5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_019f8a30-86d1-783e-997a-8d13083ec896" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_019f8a30-86d1-70ee-bf59-701ee128e4d5" xlink:to="loc_srt_NameOfMajorCustomerDomain_019f8a30-86d1-783e-997a-8d13083ec896" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_USGovernmentMember_019f8a30-86d1-7859-a10e-bdc251e23ce0" xlink:href="noc-20260930.xsd#noc_USGovernmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019f8a30-86d1-783e-997a-8d13083ec896" xlink:to="loc_noc_USGovernmentMember_019f8a30-86d1-7859-a10e-bdc251e23ce0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_InternationalCustomerMember_019f8a30-86d1-7bf4-8d81-4199718d5ff9" xlink:href="noc-20260930.xsd#noc_InternationalCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019f8a30-86d1-783e-997a-8d13083ec896" xlink:to="loc_noc_InternationalCustomerMember_019f8a30-86d1-7bf4-8d81-4199718d5ff9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_OtherCustomersMember_019f8a30-86d1-7ab8-be7d-c1c3388abdee" xlink:href="noc-20260930.xsd#noc_OtherCustomersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019f8a30-86d1-783e-997a-8d13083ec896" xlink:to="loc_noc_OtherCustomersMember_019f8a30-86d1-7ab8-be7d-c1c3388abdee" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_IntersegmentSalesMember_019f8a30-86d1-7345-8c6c-c6ac2d75e592" xlink:href="noc-20260930.xsd#noc_IntersegmentSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019f8a30-86d1-783e-997a-8d13083ec896" xlink:to="loc_noc_IntersegmentSalesMember_019f8a30-86d1-7345-8c6c-c6ac2d75e592" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019f8a30-86d1-7393-9c2f-a4b04eead10d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_019f8a30-86d1-79e1-8fef-0a3816f0c583" xlink:to="loc_us-gaap_Revenues_019f8a30-86d1-7393-9c2f-a4b04eead10d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_RevenuefromContractwithCustomerPercentage_019f8a30-86d2-7e96-883b-a5f5129b660a" xlink:href="noc-20260930.xsd#noc_RevenuefromContractwithCustomerPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_019f8a30-86d1-79e1-8fef-0a3816f0c583" xlink:to="loc_noc_RevenuefromContractwithCustomerPercentage_019f8a30-86d2-7e96-883b-a5f5129b660a" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/SegmentInformationUnauditedSalesbyContractTypeDetails3" xlink:type="simple" xlink:href="noc-20260930.xsd#SegmentInformationUnauditedSalesbyContractTypeDetails3"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/SegmentInformationUnauditedSalesbyContractTypeDetails3" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019f8a30-86d2-7407-bb0c-f57d6600a688" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8a30-86d2-7a42-a824-53ffbf3ee2ca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8a30-86d2-7407-bb0c-f57d6600a688" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8a30-86d2-7a42-a824-53ffbf3ee2ca" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d2-7844-a3eb-b4d66f68a484" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8a30-86d2-7a42-a824-53ffbf3ee2ca" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d2-7844-a3eb-b4d66f68a484" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8a30-86d2-7844-a3eb-b4d66f68a484_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d2-7844-a3eb-b4d66f68a484" xlink:to="loc_us-gaap_SegmentDomain_019f8a30-86d2-7844-a3eb-b4d66f68a484_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8a30-86d2-703f-84ab-cb6e33160428" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d2-7844-a3eb-b4d66f68a484" xlink:to="loc_us-gaap_SegmentDomain_019f8a30-86d2-703f-84ab-cb6e33160428" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_AeronauticsSystemsMember_019f8a30-86d2-76d3-980a-d3a282e09947" xlink:href="noc-20260930.xsd#noc_AeronauticsSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d2-703f-84ab-cb6e33160428" xlink:to="loc_noc_AeronauticsSystemsMember_019f8a30-86d2-76d3-980a-d3a282e09947" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_DefenseSystemsMember_019f8a30-86d2-7861-9f61-88db65c61c9b" xlink:href="noc-20260930.xsd#noc_DefenseSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d2-703f-84ab-cb6e33160428" xlink:to="loc_noc_DefenseSystemsMember_019f8a30-86d2-7861-9f61-88db65c61c9b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_MissionSystemsMember_019f8a30-86d2-76f2-8f3b-aa0d7df763b2" xlink:href="noc-20260930.xsd#noc_MissionSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d2-703f-84ab-cb6e33160428" xlink:to="loc_noc_MissionSystemsMember_019f8a30-86d2-76f2-8f3b-aa0d7df763b2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_SpaceSystemsMember_019f8a30-86d2-76f9-8023-fc31c9855de3" xlink:href="noc-20260930.xsd#noc_SpaceSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d2-703f-84ab-cb6e33160428" xlink:to="loc_noc_SpaceSystemsMember_019f8a30-86d2-76f9-8023-fc31c9855de3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019f8a30-86d2-7dc5-bb47-135e2561ee80" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8a30-86d2-7a42-a824-53ffbf3ee2ca" xlink:to="loc_srt_ConsolidationItemsAxis_019f8a30-86d2-7dc5-bb47-135e2561ee80" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019f8a30-86d2-7dc5-bb47-135e2561ee80_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019f8a30-86d2-7dc5-bb47-135e2561ee80" xlink:to="loc_srt_ConsolidationItemsDomain_019f8a30-86d2-7dc5-bb47-135e2561ee80_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019f8a30-86d2-73af-9718-7952b0345b81" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019f8a30-86d2-7dc5-bb47-135e2561ee80" xlink:to="loc_srt_ConsolidationItemsDomain_019f8a30-86d2-73af-9718-7952b0345b81" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019f8a30-86d2-7ed3-a68a-4dde690eb128" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019f8a30-86d2-73af-9718-7952b0345b81" xlink:to="loc_us-gaap_OperatingSegmentsMember_019f8a30-86d2-7ed3-a68a-4dde690eb128" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerBasisOfPricingAxis_019f8a30-86d2-7b37-ba0b-65d380323b01" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerBasisOfPricingAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8a30-86d2-7a42-a824-53ffbf3ee2ca" xlink:to="loc_us-gaap_ContractWithCustomerBasisOfPricingAxis_019f8a30-86d2-7b37-ba0b-65d380323b01" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_019f8a30-86d2-7b37-ba0b-65d380323b01_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerBasisOfPricingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ContractWithCustomerBasisOfPricingAxis_019f8a30-86d2-7b37-ba0b-65d380323b01" xlink:to="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_019f8a30-86d2-7b37-ba0b-65d380323b01_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_019f8a30-86d2-7f6c-bf59-6e056ffe2464" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerBasisOfPricingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ContractWithCustomerBasisOfPricingAxis_019f8a30-86d2-7b37-ba0b-65d380323b01" xlink:to="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_019f8a30-86d2-7f6c-bf59-6e056ffe2464" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_CostReimbursableMember_019f8a30-86d2-7bc0-945b-443e74bd7c82" xlink:href="noc-20260930.xsd#noc_CostReimbursableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_019f8a30-86d2-7f6c-bf59-6e056ffe2464" xlink:to="loc_noc_CostReimbursableMember_019f8a30-86d2-7bc0-945b-443e74bd7c82" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FixedPriceContractMember_019f8a30-86d2-7d35-9cb9-b60836d5c132" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FixedPriceContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_019f8a30-86d2-7f6c-bf59-6e056ffe2464" xlink:to="loc_us-gaap_FixedPriceContractMember_019f8a30-86d2-7d35-9cb9-b60836d5c132" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_IntersegmentSalesMember_019f8a30-86d2-70ef-a5fe-56c90e18728a" xlink:href="noc-20260930.xsd#noc_IntersegmentSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_019f8a30-86d2-7f6c-bf59-6e056ffe2464" xlink:to="loc_noc_IntersegmentSalesMember_019f8a30-86d2-70ef-a5fe-56c90e18728a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019f8a30-86d2-772e-8572-002aba59e10e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8a30-86d2-7407-bb0c-f57d6600a688" xlink:to="loc_us-gaap_Revenues_019f8a30-86d2-772e-8572-002aba59e10e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_RevenuefromContractwithCustomerPercentage_019f8a30-86d2-7050-81d3-c96102802286" xlink:href="noc-20260930.xsd#noc_RevenuefromContractwithCustomerPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8a30-86d2-7407-bb0c-f57d6600a688" xlink:to="loc_noc_RevenuefromContractwithCustomerPercentage_019f8a30-86d2-7050-81d3-c96102802286" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/SegmentInformationUnauditedSalesbyGeographicLocationDetails4" xlink:type="simple" xlink:href="noc-20260930.xsd#SegmentInformationUnauditedSalesbyGeographicLocationDetails4"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/SegmentInformationUnauditedSalesbyGeographicLocationDetails4" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019f8a30-86d2-7c21-a2d6-5ba8abaaa64f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019f8a30-86d2-7de9-b6f5-22ba5ed7efb9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019f8a30-86d2-7c21-a2d6-5ba8abaaa64f" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019f8a30-86d2-7de9-b6f5-22ba5ed7efb9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d2-7b54-ba1c-4be2688b27a5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019f8a30-86d2-7de9-b6f5-22ba5ed7efb9" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d2-7b54-ba1c-4be2688b27a5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8a30-86d2-7b54-ba1c-4be2688b27a5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d2-7b54-ba1c-4be2688b27a5" xlink:to="loc_us-gaap_SegmentDomain_019f8a30-86d2-7b54-ba1c-4be2688b27a5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8a30-86d2-79c6-854e-2bafe52632f1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d2-7b54-ba1c-4be2688b27a5" xlink:to="loc_us-gaap_SegmentDomain_019f8a30-86d2-79c6-854e-2bafe52632f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_AeronauticsSystemsMember_019f8a30-86d2-76d3-98fe-29fb70b9db32" xlink:href="noc-20260930.xsd#noc_AeronauticsSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d2-79c6-854e-2bafe52632f1" xlink:to="loc_noc_AeronauticsSystemsMember_019f8a30-86d2-76d3-98fe-29fb70b9db32" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_DefenseSystemsMember_019f8a30-86d2-7c01-8bf9-bbd14bd34eec" xlink:href="noc-20260930.xsd#noc_DefenseSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d2-79c6-854e-2bafe52632f1" xlink:to="loc_noc_DefenseSystemsMember_019f8a30-86d2-7c01-8bf9-bbd14bd34eec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_MissionSystemsMember_019f8a30-86d2-72db-8d40-09e7668c9a56" xlink:href="noc-20260930.xsd#noc_MissionSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d2-79c6-854e-2bafe52632f1" xlink:to="loc_noc_MissionSystemsMember_019f8a30-86d2-72db-8d40-09e7668c9a56" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_SpaceSystemsMember_019f8a30-86d2-75f0-8cd2-bc7b4f9a26f2" xlink:href="noc-20260930.xsd#noc_SpaceSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d2-79c6-854e-2bafe52632f1" xlink:to="loc_noc_SpaceSystemsMember_019f8a30-86d2-75f0-8cd2-bc7b4f9a26f2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019f8a30-86d2-7f50-98ff-eb586180b0ae" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019f8a30-86d2-7de9-b6f5-22ba5ed7efb9" xlink:to="loc_srt_ConsolidationItemsAxis_019f8a30-86d2-7f50-98ff-eb586180b0ae" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019f8a30-86d2-7f50-98ff-eb586180b0ae_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_019f8a30-86d2-7f50-98ff-eb586180b0ae" xlink:to="loc_srt_ConsolidationItemsDomain_019f8a30-86d2-7f50-98ff-eb586180b0ae_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019f8a30-86d2-77aa-8ac2-3a7026dff59b" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_019f8a30-86d2-7f50-98ff-eb586180b0ae" xlink:to="loc_srt_ConsolidationItemsDomain_019f8a30-86d2-77aa-8ac2-3a7026dff59b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019f8a30-86d2-7cff-9e5b-0c321f964721" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019f8a30-86d2-77aa-8ac2-3a7026dff59b" xlink:to="loc_us-gaap_OperatingSegmentsMember_019f8a30-86d2-7cff-9e5b-0c321f964721" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019f8a30-86d2-7a7c-afb2-52c0a4b21ab6" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_019f8a30-86d2-7de9-b6f5-22ba5ed7efb9" xlink:to="loc_srt_StatementGeographicalAxis_019f8a30-86d2-7a7c-afb2-52c0a4b21ab6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019f8a30-86d2-7a7c-afb2-52c0a4b21ab6_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019f8a30-86d2-7a7c-afb2-52c0a4b21ab6" xlink:to="loc_srt_SegmentGeographicalDomain_019f8a30-86d2-7a7c-afb2-52c0a4b21ab6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019f8a30-86d2-709a-bd89-762c0964c437" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019f8a30-86d2-7a7c-afb2-52c0a4b21ab6" xlink:to="loc_srt_SegmentGeographicalDomain_019f8a30-86d2-709a-bd89-762c0964c437" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019f8a30-86d2-7fbd-abe0-48972628cc9f" xlink:href="https://xbrl.sec.gov/country/2026/country-2026.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019f8a30-86d2-709a-bd89-762c0964c437" xlink:to="loc_country_US_019f8a30-86d2-7fbd-abe0-48972628cc9f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_019f8a30-86d2-7d1d-84d2-4cb02c6dbd57" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019f8a30-86d2-709a-bd89-762c0964c437" xlink:to="loc_srt_AsiaPacificMember_019f8a30-86d2-7d1d-84d2-4cb02c6dbd57" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EuropeMember_019f8a30-86d2-7588-b816-9e393afc308f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_EuropeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019f8a30-86d2-709a-bd89-762c0964c437" xlink:to="loc_srt_EuropeMember_019f8a30-86d2-7588-b816-9e393afc308f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_AllOtherGeographicRegionDomain_019f8a30-86d2-7529-8335-ee6eccc078ba" xlink:href="noc-20260930.xsd#noc_AllOtherGeographicRegionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019f8a30-86d2-709a-bd89-762c0964c437" xlink:to="loc_noc_AllOtherGeographicRegionDomain_019f8a30-86d2-7529-8335-ee6eccc078ba" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_IntersegmentSalesMember_019f8a30-86d2-7169-914d-2bec78f6ef0d" xlink:href="noc-20260930.xsd#noc_IntersegmentSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019f8a30-86d2-709a-bd89-762c0964c437" xlink:to="loc_noc_IntersegmentSalesMember_019f8a30-86d2-7169-914d-2bec78f6ef0d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019f8a30-86d2-7d36-88d8-2a3fdc9731e6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019f8a30-86d2-7c21-a2d6-5ba8abaaa64f" xlink:to="loc_us-gaap_Revenues_019f8a30-86d2-7d36-88d8-2a3fdc9731e6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_RevenuefromContractwithCustomerPercentage_019f8a30-86d2-75de-8f18-4fe0fe822dca" xlink:href="noc-20260930.xsd#noc_RevenuefromContractwithCustomerPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_019f8a30-86d2-7c21-a2d6-5ba8abaaa64f" xlink:to="loc_noc_RevenuefromContractwithCustomerPercentage_019f8a30-86d2-75de-8f18-4fe0fe822dca" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.northropgrumman.com/role/SegmentInformationUnauditedCapitalExpendituresandDepreciationandAmortizationDetails5" xlink:type="simple" xlink:href="noc-20260930.xsd#SegmentInformationUnauditedCapitalExpendituresandDepreciationandAmortizationDetails5"/>
  <link:definitionLink xlink:role="http://www.northropgrumman.com/role/SegmentInformationUnauditedCapitalExpendituresandDepreciationandAmortizationDetails5" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019f8a30-86d2-7fe5-9779-516b523a8e14" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8a30-86d2-7d94-b7e1-e2da11935bcc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8a30-86d2-7fe5-9779-516b523a8e14" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8a30-86d2-7d94-b7e1-e2da11935bcc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d2-7a51-b21c-0d9d93895002" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f8a30-86d2-7d94-b7e1-e2da11935bcc" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d2-7a51-b21c-0d9d93895002" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8a30-86d2-7a51-b21c-0d9d93895002_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d2-7a51-b21c-0d9d93895002" xlink:to="loc_us-gaap_SegmentDomain_019f8a30-86d2-7a51-b21c-0d9d93895002_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f8a30-86d2-7b3f-82de-a2ce1238f34a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019f8a30-86d2-7a51-b21c-0d9d93895002" xlink:to="loc_us-gaap_SegmentDomain_019f8a30-86d2-7b3f-82de-a2ce1238f34a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_AeronauticsSystemsMember_019f8a30-86d2-77c1-a738-f5a7b141f4db" xlink:href="noc-20260930.xsd#noc_AeronauticsSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d2-7b3f-82de-a2ce1238f34a" xlink:to="loc_noc_AeronauticsSystemsMember_019f8a30-86d2-77c1-a738-f5a7b141f4db" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_DefenseSystemsMember_019f8a30-86d2-7f87-bb94-1d1bcca89df8" xlink:href="noc-20260930.xsd#noc_DefenseSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d2-7b3f-82de-a2ce1238f34a" xlink:to="loc_noc_DefenseSystemsMember_019f8a30-86d2-7f87-bb94-1d1bcca89df8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_MissionSystemsMember_019f8a30-86d2-78fb-9d93-e491a8c2117e" xlink:href="noc-20260930.xsd#noc_MissionSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d2-7b3f-82de-a2ce1238f34a" xlink:to="loc_noc_MissionSystemsMember_019f8a30-86d2-78fb-9d93-e491a8c2117e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_SpaceSystemsMember_019f8a30-86d2-74b6-a35d-5f794c92b674" xlink:href="noc-20260930.xsd#noc_SpaceSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d2-7b3f-82de-a2ce1238f34a" xlink:to="loc_noc_SpaceSystemsMember_019f8a30-86d2-74b6-a35d-5f794c92b674" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateMember_019f8a30-86d2-7e5c-a9ab-edb612b448cd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f8a30-86d2-7b3f-82de-a2ce1238f34a" xlink:to="loc_us-gaap_CorporateMember_019f8a30-86d2-7e5c-a9ab-edb612b448cd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentExpenditureAdditionToLongLivedAssets_019f8a30-86d2-782f-b085-a460018f3efd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentExpenditureAdditionToLongLivedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8a30-86d2-7fe5-9779-516b523a8e14" xlink:to="loc_us-gaap_SegmentExpenditureAdditionToLongLivedAssets_019f8a30-86d2-782f-b085-a460018f3efd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_019f8a30-86d2-7381-bc26-8a4b609fdb4a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f8a30-86d2-7fe5-9779-516b523a8e14" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_019f8a30-86d2-7381-bc26-8a4b609fdb4a" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2026/ecd-2026.xsd#IndividualsOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ecd_AllIndividualsMember" xlink:href="https://xbrl.sec.gov/ecd/2026/ecd-2026.xsd#ecd_AllIndividualsMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_noc_MarkA.WelshIIIMember_019f8a30-84f4-7d4f-955d-8f45ef149847" xlink:href="noc-20260930.xsd#noc_MarkA.WelshIIIMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllIndividualsMember" xlink:to="loc_noc_MarkA.WelshIIIMember_019f8a30-84f4-7d4f-955d-8f45ef149847" xlink:type="arc" order="2"/>
  </link:definitionLink>
</link:linkbase>
