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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019ea99f-c986-7be8-a412-f46b8d75fc68,g:30107682-d5ef-4068-83c8-93923d0ebad6-->
<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.boeing.com/role/Cover" xlink:type="simple" xlink:href="ba-20260630.xsd#Cover"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/Cover" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitiesTable_019ea99f-cb7e-719a-9c06-9ed9e73f5849" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntitiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_EntitiesTable_019ea99f-cb7e-719a-9c06-9ed9e73f5849" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cb7e-7ee3-996d-31f21cdfe27c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_EntitiesTable_019ea99f-cb7e-719a-9c06-9ed9e73f5849" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cb7e-7ee3-996d-31f21cdfe27c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7e-7ee3-996d-31f21cdfe27c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cb7e-7ee3-996d-31f21cdfe27c" xlink:to="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7e-7ee3-996d-31f21cdfe27c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7e-7022-9675-c41f1e47421d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cb7e-7ee3-996d-31f21cdfe27c" xlink:to="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7e-7022-9675-c41f1e47421d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019ea99f-cb7e-7be1-9482-8fef4940e6e8" 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_ClassOfStockDomain_019ea99f-cb7e-7022-9675-c41f1e47421d" xlink:to="loc_us-gaap_CommonStockMember_019ea99f-cb7e-7be1-9482-8fef4940e6e8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_DepositarySharesMember_019ea99f-cb7e-792f-ae1b-5a9a6fb38f75" xlink:href="ba-20260630.xsd#ba_DepositarySharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7e-7022-9675-c41f1e47421d" xlink:to="loc_ba_DepositarySharesMember_019ea99f-cb7e-792f-ae1b-5a9a6fb38f75" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_019ea99f-cb7e-73dd-9998-2b3296ceb9fa" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_DocumentType_019ea99f-cb7e-73dd-9998-2b3296ceb9fa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentQuarterlyReport_019ea99f-cb7e-7874-9278-f35f4c9205b5" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentQuarterlyReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_DocumentQuarterlyReport_019ea99f-cb7e-7874-9278-f35f4c9205b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_019ea99f-cb7e-72b5-8f7d-65b257631bd0" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_DocumentPeriodEndDate_019ea99f-cb7e-72b5-8f7d-65b257631bd0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_019ea99f-cb7e-7f0d-9168-94debe5ae0ef" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentTransitionReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_DocumentTransitionReport_019ea99f-cb7e-7f0d-9168-94debe5ae0ef" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_019ea99f-cb7e-71eb-bf8c-51d7f37159e1" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_EntityFileNumber_019ea99f-cb7e-71eb-bf8c-51d7f37159e1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_019ea99f-cb7e-710d-8e97-317a9c0f8f77" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_EntityRegistrantName_019ea99f-cb7e-710d-8e97-317a9c0f8f77" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_019ea99f-cb7e-7bfa-ad38-25c7dfc244e3" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_EntityIncorporationStateCountryCode_019ea99f-cb7e-7bfa-ad38-25c7dfc244e3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_019ea99f-cb7e-7ed5-a176-a583702883ca" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_EntityTaxIdentificationNumber_019ea99f-cb7e-7ed5-a176-a583702883ca" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_019ea99f-cb7e-72a9-8d5d-a238f32e7fab" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_EntityAddressAddressLine1_019ea99f-cb7e-72a9-8d5d-a238f32e7fab" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_019ea99f-cb7e-796a-8d2d-327ec7938d16" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_EntityAddressCityOrTown_019ea99f-cb7e-796a-8d2d-327ec7938d16" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_019ea99f-cb7e-77ad-a307-fd319827e941" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_EntityAddressStateOrProvince_019ea99f-cb7e-77ad-a307-fd319827e941" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_019ea99f-cb7e-72b9-87f8-934ecb4ef1e1" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_EntityAddressPostalZipCode_019ea99f-cb7e-72b9-87f8-934ecb4ef1e1" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_019ea99f-cb7e-711e-918b-1b7476acf866" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_CityAreaCode_019ea99f-cb7e-711e-918b-1b7476acf866" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_019ea99f-cb7e-7b11-891d-4d6dc299dd9d" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_LocalPhoneNumber_019ea99f-cb7e-7b11-891d-4d6dc299dd9d" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_019ea99f-cb7e-7804-811b-4fd689703187" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_Security12bTitle_019ea99f-cb7e-7804-811b-4fd689703187" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_019ea99f-cb7e-7521-ac86-6c23afd80ed2" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_TradingSymbol_019ea99f-cb7e-7521-ac86-6c23afd80ed2" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_019ea99f-cb7e-7add-8ad2-888eca7b23d4" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_SecurityExchangeName_019ea99f-cb7e-7add-8ad2-888eca7b23d4" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_019ea99f-cb7e-7c63-a84a-a0d70f741fe1" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCurrentReportingStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_EntityCurrentReportingStatus_019ea99f-cb7e-7c63-a84a-a0d70f741fe1" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_019ea99f-cb7e-7430-873f-864ecd47dfae" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_EntityInteractiveDataCurrent_019ea99f-cb7e-7430-873f-864ecd47dfae" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_019ea99f-cb7e-7fe1-bf26-290bc8047a2b" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFilerCategory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_EntityFilerCategory_019ea99f-cb7e-7fe1-bf26-290bc8047a2b" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_019ea99f-cb7e-7027-b1d2-f78dd84a9c4d" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntitySmallBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_EntitySmallBusiness_019ea99f-cb7e-7027-b1d2-f78dd84a9c4d" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_019ea99f-cb7e-7636-b754-ab0656e67145" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_EntityEmergingGrowthCompany_019ea99f-cb7e-7636-b754-ab0656e67145" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_019ea99f-cb7e-7861-904e-fbe8b85ed338" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityShellCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_EntityShellCompany_019ea99f-cb7e-7861-904e-fbe8b85ed338" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_019ea99f-cb7e-77d6-8605-8d7eee69c736" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_019ea99f-cb7e-77d6-8605-8d7eee69c736" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_019ea99f-cb7e-76c4-b9e0-8d4b8a604aed" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_AmendmentFlag_019ea99f-cb7e-76c4-b9e0-8d4b8a604aed" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_019ea99f-cb7e-71c0-a163-ee020274eca3" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentFiscalYearFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_DocumentFiscalYearFocus_019ea99f-cb7e-71c0-a163-ee020274eca3" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_019ea99f-cb7e-717b-88fb-263b7139ee7e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_DocumentFiscalPeriodFocus_019ea99f-cb7e-717b-88fb-263b7139ee7e" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_019ea99f-cb7e-7679-8b68-61d5918a07b2" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_EntityCentralIndexKey_019ea99f-cb7e-7679-8b68-61d5918a07b2" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_019ea99f-cb7e-785a-8776-7f9d3f649acc" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_019ea99f-cb7e-7703-82d4-84a89274e2b1" xlink:to="loc_dei_CurrentFiscalYearEndDate_019ea99f-cb7e-785a-8776-7f9d3f649acc" xlink:type="arc" order="28"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/CondensedConsolidatedStatementsofOperations" xlink:type="simple" xlink:href="ba-20260630.xsd#CondensedConsolidatedStatementsofOperations"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/CondensedConsolidatedStatementsofOperations" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" 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_019ea99f-cb7e-7098-ac7e-0d53324a55d8" 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_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_StatementTable_019ea99f-cb7e-7098-ac7e-0d53324a55d8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019ea99f-cb7e-71a8-b47f-14350d1c43eb" 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_019ea99f-cb7e-7098-ac7e-0d53324a55d8" xlink:to="loc_srt_ProductOrServiceAxis_019ea99f-cb7e-71a8-b47f-14350d1c43eb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019ea99f-cb7e-71a8-b47f-14350d1c43eb_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_019ea99f-cb7e-71a8-b47f-14350d1c43eb" xlink:to="loc_srt_ProductsAndServicesDomain_019ea99f-cb7e-71a8-b47f-14350d1c43eb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019ea99f-cb7e-77f8-86f0-fb8426a4bfaf" 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_019ea99f-cb7e-71a8-b47f-14350d1c43eb" xlink:to="loc_srt_ProductsAndServicesDomain_019ea99f-cb7e-77f8-86f0-fb8426a4bfaf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductMember_019ea99f-cb7e-7b87-8244-1bffb1fddaae" 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_019ea99f-cb7e-77f8-86f0-fb8426a4bfaf" xlink:to="loc_us-gaap_ProductMember_019ea99f-cb7e-7b87-8244-1bffb1fddaae" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_019ea99f-cb7e-7aac-9db9-98abe0894aa1" 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_019ea99f-cb7e-77f8-86f0-fb8426a4bfaf" xlink:to="loc_us-gaap_ServiceMember_019ea99f-cb7e-7aac-9db9-98abe0894aa1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019ea99f-cb7e-767a-9fe9-69940da3415a" 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_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_Revenues_019ea99f-cb7e-767a-9fe9-69940da3415a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_019ea99f-cb7e-7929-8188-3b095cfb78eb" 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_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_019ea99f-cb7e-7929-8188-3b095cfb78eb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenue_019ea99f-cb7e-76ab-8984-6937407d5926" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostOfRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_CostOfRevenue_019ea99f-cb7e-76ab-8984-6937407d5926" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_019ea99f-cb7e-71e6-bd95-bbe9a1e92e3f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_GrossProfit_019ea99f-cb7e-71e6-bd95-bbe9a1e92e3f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_IncomeLossfromInvestments_019ea99f-cb7e-74f2-9533-36bc46c1e08c" xlink:href="ba-20260630.xsd#ba_IncomeLossfromInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_ba_IncomeLossfromInvestments_019ea99f-cb7e-74f2-9533-36bc46c1e08c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_019ea99f-cb7e-7775-a13e-930519ef6cac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_019ea99f-cb7e-7775-a13e-930519ef6cac" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_019ea99f-cb7e-7f07-a744-86dbc0b2149a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_019ea99f-cb7e-7f07-a744-86dbc0b2149a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnDispositionOfAssets_019ea99f-cb7e-7f13-9451-952c9908aa9f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnDispositionOfAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_GainLossOnDispositionOfAssets_019ea99f-cb7e-7f13-9451-952c9908aa9f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019ea99f-cb7e-7556-a222-576a56816b31" 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_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_OperatingIncomeLoss_019ea99f-cb7e-7556-a222-576a56816b31" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019ea99f-cb7e-72df-9ad6-18bf107c6ca4" 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_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019ea99f-cb7e-72df-9ad6-18bf107c6ca4" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDebtExpense_019ea99f-cb7e-78be-bf1f-7d19cfc4f4e5" 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_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_InterestAndDebtExpense_019ea99f-cb7e-78be-bf1f-7d19cfc4f4e5" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019ea99f-cb7e-77d6-bb50-daa65b22ef05" 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_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019ea99f-cb7e-77d6-bb50-daa65b22ef05" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019ea99f-cb7e-765d-8f49-cc49757e8af9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019ea99f-cb7e-765d-8f49-cc49757e8af9" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019ea99f-cb7e-7ee7-8730-da9cc0639fd7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_ProfitLoss_019ea99f-cb7e-7ee7-8730-da9cc0639fd7" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019ea99f-cb7e-7357-854c-0bd7aabe50ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019ea99f-cb7e-7357-854c-0bd7aabe50ae" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019ea99f-cb7e-76da-844e-3dfa9d8cff4c" 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_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_NetIncomeLoss_019ea99f-cb7e-76da-844e-3dfa9d8cff4c" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendsIncomeStatementImpact_019ea99f-cb7e-7901-bafe-816b4d8fef25" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockDividendsIncomeStatementImpact"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_PreferredStockDividendsIncomeStatementImpact_019ea99f-cb7e-7901-bafe-816b4d8fef25" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_019ea99f-cb7e-72ac-aba9-31a8271685b7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_019ea99f-cb7e-72ac-aba9-31a8271685b7" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_019ea99f-cb7e-7264-bfce-0bd41da6eff7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_019ea99f-cb7e-7264-bfce-0bd41da6eff7" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_019ea99f-cb7e-727d-8b03-33228e9a0eee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_EarningsPerShareBasic_019ea99f-cb7e-727d-8b03-33228e9a0eee" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_019ea99f-cb7e-749e-823b-20e1f215012a" 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_StatementLineItems_019ea99f-cb7e-7e95-b849-0a150d529d55" xlink:to="loc_us-gaap_EarningsPerShareDiluted_019ea99f-cb7e-749e-823b-20e1f215012a" xlink:type="arc" order="20"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/CondensedConsolidatedStatementsofFinancialPosition" xlink:type="simple" xlink:href="ba-20260630.xsd#CondensedConsolidatedStatementsofFinancialPosition"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/CondensedConsolidatedStatementsofFinancialPosition" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7474-bf24-2f94d729cd68" 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_019ea99f-cb7e-7a51-8b29-beeec0ef81a6" 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_019ea99f-cb7e-7474-bf24-2f94d729cd68" xlink:to="loc_us-gaap_StatementTable_019ea99f-cb7e-7a51-8b29-beeec0ef81a6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cb7e-7b8e-86f8-9e308655bf96" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019ea99f-cb7e-7a51-8b29-beeec0ef81a6" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cb7e-7b8e-86f8-9e308655bf96" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7e-7b8e-86f8-9e308655bf96_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cb7e-7b8e-86f8-9e308655bf96" xlink:to="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7e-7b8e-86f8-9e308655bf96_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7e-7c5b-9b72-bb4bb2d50627" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cb7e-7b8e-86f8-9e308655bf96" xlink:to="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7e-7c5b-9b72-bb4bb2d50627" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertiblePreferredStockMember_019ea99f-cb7e-7b68-a436-de7bcb98ae22" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConvertiblePreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7e-7c5b-9b72-bb4bb2d50627" xlink:to="loc_us-gaap_ConvertiblePreferredStockMember_019ea99f-cb7e-7b68-a436-de7bcb98ae22" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_019ea99f-cb7e-7f15-b59b-961d21f78492" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7474-bf24-2f94d729cd68" xlink:to="loc_us-gaap_AssetsAbstract_019ea99f-cb7e-7f15-b59b-961d21f78492" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019ea99f-cb7e-76c2-977d-71e4388851d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019ea99f-cb7e-7f15-b59b-961d21f78492" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019ea99f-cb7e-76c2-977d-71e4388851d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermInvestments_019ea99f-cb7e-7c40-823c-ffea13f71c43" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortTermInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019ea99f-cb7e-7f15-b59b-961d21f78492" xlink:to="loc_us-gaap_ShortTermInvestments_019ea99f-cb7e-7c40-823c-ffea13f71c43" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_019ea99f-cb7e-752f-8b09-02d2c06fcd8d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019ea99f-cb7e-7f15-b59b-961d21f78492" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_019ea99f-cb7e-752f-8b09-02d2c06fcd8d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnbilledContractsReceivable_019ea99f-cb7e-7a81-8d9d-34b18a5f3cf8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnbilledContractsReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019ea99f-cb7e-7f15-b59b-961d21f78492" xlink:to="loc_us-gaap_UnbilledContractsReceivable_019ea99f-cb7e-7a81-8d9d-34b18a5f3cf8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNetOfAllowancesCustomerAdvancesAndProgressBillings_019ea99f-cb7e-738b-8362-81e543a6e9cc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryNetOfAllowancesCustomerAdvancesAndProgressBillings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019ea99f-cb7e-7f15-b59b-961d21f78492" xlink:to="loc_us-gaap_InventoryNetOfAllowancesCustomerAdvancesAndProgressBillings_019ea99f-cb7e-738b-8362-81e543a6e9cc" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsCurrent_019ea99f-cb7e-7ef3-bb6c-cdbe08ce830a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019ea99f-cb7e-7f15-b59b-961d21f78492" xlink:to="loc_us-gaap_OtherAssetsCurrent_019ea99f-cb7e-7ef3-bb6c-cdbe08ce830a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_019ea99f-cb7e-7729-8f8b-65e4f7e6c52d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019ea99f-cb7e-7f15-b59b-961d21f78492" xlink:to="loc_us-gaap_AssetsCurrent_019ea99f-cb7e-7729-8f8b-65e4f7e6c52d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_FinancingReceivablesAndOperatingLeaseEquipmentNet_019ea99f-cb7e-7f7a-9cae-76ba27f1ee6e" xlink:href="ba-20260630.xsd#ba_FinancingReceivablesAndOperatingLeaseEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019ea99f-cb7e-7f15-b59b-961d21f78492" xlink:to="loc_ba_FinancingReceivablesAndOperatingLeaseEquipmentNet_019ea99f-cb7e-7f7a-9cae-76ba27f1ee6e" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019ea99f-cb7e-7274-ab3c-e35cc48e2bc9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019ea99f-cb7e-7f15-b59b-961d21f78492" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_019ea99f-cb7e-7274-ab3c-e35cc48e2bc9" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019ea99f-cb7e-73ad-8cf0-8b0c8f5631f1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019ea99f-cb7e-7f15-b59b-961d21f78492" xlink:to="loc_us-gaap_Goodwill_019ea99f-cb7e-73ad-8cf0-8b0c8f5631f1" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_019ea99f-cb7e-75a6-aa2a-de4c44bfeee9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019ea99f-cb7e-7f15-b59b-961d21f78492" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_019ea99f-cb7e-75a6-aa2a-de4c44bfeee9" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxAssetsNet_019ea99f-cb7e-711b-b00d-03ea603a7325" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredIncomeTaxAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019ea99f-cb7e-7f15-b59b-961d21f78492" xlink:to="loc_us-gaap_DeferredIncomeTaxAssetsNet_019ea99f-cb7e-711b-b00d-03ea603a7325" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermInvestments_019ea99f-cb7e-784d-bcaa-06f63ce2db63" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019ea99f-cb7e-7f15-b59b-961d21f78492" xlink:to="loc_us-gaap_LongTermInvestments_019ea99f-cb7e-784d-bcaa-06f63ce2db63" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_019ea99f-cb7e-7922-bcf3-7144374558cc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019ea99f-cb7e-7f15-b59b-961d21f78492" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_019ea99f-cb7e-7922-bcf3-7144374558cc" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019ea99f-cb7e-7611-a87c-277ad79f042c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_019ea99f-cb7e-7f15-b59b-961d21f78492" xlink:to="loc_us-gaap_Assets_019ea99f-cb7e-7611-a87c-277ad79f042c" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019ea99f-cb7e-78cd-90bf-68d0ca102aac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7474-bf24-2f94d729cd68" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019ea99f-cb7e-78cd-90bf-68d0ca102aac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrent_019ea99f-cb7e-7c38-863d-6c00181a5cf8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019ea99f-cb7e-78cd-90bf-68d0ca102aac" xlink:to="loc_us-gaap_AccountsPayableCurrent_019ea99f-cb7e-7c38-863d-6c00181a5cf8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_019ea99f-cb7e-70a1-972b-a5e5b236bd57" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019ea99f-cb7e-78cd-90bf-68d0ca102aac" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent_019ea99f-cb7e-70a1-972b-a5e5b236bd57" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_019ea99f-cb7e-7ece-b405-b7900cd7a4e8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019ea99f-cb7e-78cd-90bf-68d0ca102aac" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_019ea99f-cb7e-7ece-b405-b7900cd7a4e8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtCurrent_019ea99f-cb7e-71bf-bf34-cea69a9e1b48" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019ea99f-cb7e-78cd-90bf-68d0ca102aac" xlink:to="loc_us-gaap_DebtCurrent_019ea99f-cb7e-71bf-bf34-cea69a9e1b48" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_019ea99f-cb7e-74ba-ae96-add4f08c3fc0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019ea99f-cb7e-78cd-90bf-68d0ca102aac" xlink:to="loc_us-gaap_LiabilitiesCurrent_019ea99f-cb7e-74ba-ae96-add4f08c3fc0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_019ea99f-cb7e-75c3-8894-8ca0581d7e8f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019ea99f-cb7e-78cd-90bf-68d0ca102aac" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_019ea99f-cb7e-75c3-8894-8ca0581d7e8f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent_019ea99f-cb7e-7946-a295-37a0d3b74f6c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019ea99f-cb7e-78cd-90bf-68d0ca102aac" xlink:to="loc_us-gaap_OtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent_019ea99f-cb7e-7946-a295-37a0d3b74f6c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPensionPlanLiabilitiesNoncurrent_019ea99f-cb7e-7d7e-8472-7cc8241b9a37" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPensionPlanLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019ea99f-cb7e-78cd-90bf-68d0ca102aac" xlink:to="loc_us-gaap_DefinedBenefitPensionPlanLiabilitiesNoncurrent_019ea99f-cb7e-7d7e-8472-7cc8241b9a37" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_019ea99f-cb7e-74d0-9552-db65bdd0ecc7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019ea99f-cb7e-78cd-90bf-68d0ca102aac" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_019ea99f-cb7e-74d0-9552-db65bdd0ecc7" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_019ea99f-cb7e-70bb-ba65-cbc1ed318f76" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019ea99f-cb7e-78cd-90bf-68d0ca102aac" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_019ea99f-cb7e-70bb-ba65-cbc1ed318f76" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019ea99f-cb7e-744f-a0ba-aa46dfe342bb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019ea99f-cb7e-78cd-90bf-68d0ca102aac" xlink:to="loc_us-gaap_Liabilities_019ea99f-cb7e-744f-a0ba-aa46dfe342bb" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019ea99f-cb7e-7134-abca-72ca9c8456e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019ea99f-cb7e-78cd-90bf-68d0ca102aac" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019ea99f-cb7e-7134-abca-72ca9c8456e1" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValue_019ea99f-cb7e-718c-904d-7dadb3c7caa5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019ea99f-cb7e-7134-abca-72ca9c8456e1" xlink:to="loc_us-gaap_PreferredStockValue_019ea99f-cb7e-718c-904d-7dadb3c7caa5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_019ea99f-cb7e-7695-a2d2-39cfb36a577f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019ea99f-cb7e-7134-abca-72ca9c8456e1" xlink:to="loc_us-gaap_CommonStockValue_019ea99f-cb7e-7695-a2d2-39cfb36a577f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital_019ea99f-cb7e-7852-adf7-6911d39454d8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019ea99f-cb7e-7134-abca-72ca9c8456e1" xlink:to="loc_us-gaap_AdditionalPaidInCapital_019ea99f-cb7e-7852-adf7-6911d39454d8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonValue_019ea99f-cb7e-7ecd-ac32-27f51dbf5063" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019ea99f-cb7e-7134-abca-72ca9c8456e1" xlink:to="loc_us-gaap_TreasuryStockCommonValue_019ea99f-cb7e-7ecd-ac32-27f51dbf5063" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019ea99f-cb7e-73f4-8a6b-60a69e0fda44" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019ea99f-cb7e-7134-abca-72ca9c8456e1" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019ea99f-cb7e-73f4-8a6b-60a69e0fda44" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019ea99f-cb7e-71b0-8be2-38a49aa726b2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019ea99f-cb7e-7134-abca-72ca9c8456e1" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019ea99f-cb7e-71b0-8be2-38a49aa726b2" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019ea99f-cb7e-7886-b40d-9c28d16df5b7" 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_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019ea99f-cb7e-7134-abca-72ca9c8456e1" xlink:to="loc_us-gaap_StockholdersEquity_019ea99f-cb7e-7886-b40d-9c28d16df5b7" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterest_019ea99f-cb7e-7937-8e73-65aa90e11cf1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MinorityInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019ea99f-cb7e-7134-abca-72ca9c8456e1" xlink:to="loc_us-gaap_MinorityInterest_019ea99f-cb7e-7937-8e73-65aa90e11cf1" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019ea99f-cb7e-7991-9d91-1ee213b4d801" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_019ea99f-cb7e-7134-abca-72ca9c8456e1" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019ea99f-cb7e-7991-9d91-1ee213b4d801" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_019ea99f-cb7e-798d-8712-82c09a4c95cd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_019ea99f-cb7e-78cd-90bf-68d0ca102aac" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_019ea99f-cb7e-798d-8712-82c09a4c95cd" xlink:type="arc" order="13"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/CondensedConsolidatedStatementsofFinancialPositionParenthetical" xlink:type="simple" xlink:href="ba-20260630.xsd#CondensedConsolidatedStatementsofFinancialPositionParenthetical"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/CondensedConsolidatedStatementsofFinancialPositionParenthetical" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e2f-9ee7-e336fd399ba2" 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_019ea99f-cb7e-714e-90be-9685d2648619" 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_019ea99f-cb7e-7e2f-9ee7-e336fd399ba2" xlink:to="loc_us-gaap_StatementTable_019ea99f-cb7e-714e-90be-9685d2648619" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cb7e-7a11-bbbe-57c2ecd69b81" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019ea99f-cb7e-714e-90be-9685d2648619" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cb7e-7a11-bbbe-57c2ecd69b81" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7e-7a11-bbbe-57c2ecd69b81_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cb7e-7a11-bbbe-57c2ecd69b81" xlink:to="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7e-7a11-bbbe-57c2ecd69b81_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7e-79e9-97b6-bd3f2404e3e7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cb7e-7a11-bbbe-57c2ecd69b81" xlink:to="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7e-79e9-97b6-bd3f2404e3e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertiblePreferredStockMember_019ea99f-cb7e-7240-9d17-d77c230e2363" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConvertiblePreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7e-79e9-97b6-bd3f2404e3e7" xlink:to="loc_us-gaap_ConvertiblePreferredStockMember_019ea99f-cb7e-7240-9d17-d77c230e2363" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019ea99f-cb7e-7417-9828-101535be424d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e2f-9ee7-e336fd399ba2" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019ea99f-cb7e-7417-9828-101535be424d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedComputerSoftwareAccumulatedAmortization_019ea99f-cb7e-7ffd-a4b0-29f41d5e2355" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalizedComputerSoftwareAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e2f-9ee7-e336fd399ba2" xlink:to="loc_us-gaap_CapitalizedComputerSoftwareAccumulatedAmortization_019ea99f-cb7e-7ffd-a4b0-29f41d5e2355" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendRatePercentage_019ea99f-cb7e-7540-9e85-b0e9e767b761" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockDividendRatePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e2f-9ee7-e336fd399ba2" xlink:to="loc_us-gaap_PreferredStockDividendRatePercentage_019ea99f-cb7e-7540-9e85-b0e9e767b761" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_019ea99f-cb7e-7efc-9c91-74d6bd16ae44" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e2f-9ee7-e336fd399ba2" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_019ea99f-cb7e-7efc-9c91-74d6bd16ae44" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_019ea99f-cb7e-76e2-854e-e55b5deccb0d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e2f-9ee7-e336fd399ba2" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_019ea99f-cb7e-76e2-854e-e55b5deccb0d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_019ea99f-cb7e-70ec-9763-5ec0ae87db50" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e2f-9ee7-e336fd399ba2" xlink:to="loc_us-gaap_PreferredStockSharesIssued_019ea99f-cb7e-70ec-9763-5ec0ae87db50" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockLiquidationPreferenceValue_019ea99f-cb7e-7e7f-87f7-04de9b31ab2d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockLiquidationPreferenceValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e2f-9ee7-e336fd399ba2" xlink:to="loc_us-gaap_PreferredStockLiquidationPreferenceValue_019ea99f-cb7e-7e7f-87f7-04de9b31ab2d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_019ea99f-cb7e-7162-8f92-3833d213a1d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e2f-9ee7-e336fd399ba2" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_019ea99f-cb7e-7162-8f92-3833d213a1d2" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_019ea99f-cb7e-7a5a-a2d5-c3686f62245b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e2f-9ee7-e336fd399ba2" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_019ea99f-cb7e-7a5a-a2d5-c3686f62245b" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_019ea99f-cb7e-701b-94d0-27ce7c38a695" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e2f-9ee7-e336fd399ba2" xlink:to="loc_us-gaap_CommonStockSharesIssued_019ea99f-cb7e-701b-94d0-27ce7c38a695" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_019ea99f-cb7e-783d-980b-8314aebfb613" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019ea99f-cb7e-7e2f-9ee7-e336fd399ba2" xlink:to="loc_us-gaap_TreasuryStockCommonShares_019ea99f-cb7e-783d-980b-8314aebfb613" xlink:type="arc" order="10"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/CondensedConsolidatedStatementsofEquity" xlink:type="simple" xlink:href="ba-20260630.xsd#CondensedConsolidatedStatementsofEquity"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/CondensedConsolidatedStatementsofEquity" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019ea99f-cb7f-7a04-975e-e8e009e6c8d8" 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_019ea99f-cb7f-79e6-8ae5-1ebea41a7143" 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_019ea99f-cb7f-7a04-975e-e8e009e6c8d8" xlink:to="loc_us-gaap_StatementTable_019ea99f-cb7f-79e6-8ae5-1ebea41a7143" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019ea99f-cb7f-7b56-aad4-3ad0de438878" 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_019ea99f-cb7f-79e6-8ae5-1ebea41a7143" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019ea99f-cb7f-7b56-aad4-3ad0de438878" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019ea99f-cb7f-7b56-aad4-3ad0de438878_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_019ea99f-cb7f-7b56-aad4-3ad0de438878" xlink:to="loc_us-gaap_EquityComponentDomain_019ea99f-cb7f-7b56-aad4-3ad0de438878_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019ea99f-cb7f-751d-92b4-eac672eaee50" 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_019ea99f-cb7f-7b56-aad4-3ad0de438878" xlink:to="loc_us-gaap_EquityComponentDomain_019ea99f-cb7f-751d-92b4-eac672eaee50" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockMember_019ea99f-cb7f-79d4-8841-a805dbbb09da" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019ea99f-cb7f-751d-92b4-eac672eaee50" xlink:to="loc_us-gaap_PreferredStockMember_019ea99f-cb7f-79d4-8841-a805dbbb09da" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019ea99f-cb7f-78d8-b889-6f61b06152f2" 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_019ea99f-cb7f-751d-92b4-eac672eaee50" xlink:to="loc_us-gaap_CommonStockMember_019ea99f-cb7f-78d8-b889-6f61b06152f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019ea99f-cb7f-777e-ae05-55d18e903b3b" 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_019ea99f-cb7f-751d-92b4-eac672eaee50" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019ea99f-cb7f-777e-ae05-55d18e903b3b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_019ea99f-cb7f-7191-b2e3-07ebba8c1387" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019ea99f-cb7f-751d-92b4-eac672eaee50" xlink:to="loc_us-gaap_TreasuryStockCommonMember_019ea99f-cb7f-7191-b2e3-07ebba8c1387" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019ea99f-cb7f-7cd9-a9f0-371d01e050c9" 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_019ea99f-cb7f-751d-92b4-eac672eaee50" xlink:to="loc_us-gaap_RetainedEarningsMember_019ea99f-cb7f-7cd9-a9f0-371d01e050c9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ea99f-cb7f-79e0-add9-40e022d0543e" 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_019ea99f-cb7f-751d-92b4-eac672eaee50" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ea99f-cb7f-79e0-add9-40e022d0543e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_019ea99f-cb7f-76fe-9408-71f9c852bf34" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019ea99f-cb7f-751d-92b4-eac672eaee50" xlink:to="loc_us-gaap_NoncontrollingInterestMember_019ea99f-cb7f-76fe-9408-71f9c852bf34" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cb7f-7f93-b474-a3d9b4e1a495" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019ea99f-cb7f-79e6-8ae5-1ebea41a7143" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cb7f-7f93-b474-a3d9b4e1a495" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7f-7f93-b474-a3d9b4e1a495_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cb7f-7f93-b474-a3d9b4e1a495" xlink:to="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7f-7f93-b474-a3d9b4e1a495_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7f-7b0a-a4e6-c5977225aefe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cb7f-7f93-b474-a3d9b4e1a495" xlink:to="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7f-7b0a-a4e6-c5977225aefe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertiblePreferredStockMember_019ea99f-cb7f-711d-8562-85d1e09a6e47" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConvertiblePreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019ea99f-cb7f-7b0a-a4e6-c5977225aefe" xlink:to="loc_us-gaap_ConvertiblePreferredStockMember_019ea99f-cb7f-711d-8562-85d1e09a6e47" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ea99f-cb7f-77cd-b331-892170041d3e" 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_019ea99f-cb7f-7a04-975e-e8e009e6c8d8" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ea99f-cb7f-77cd-b331-892170041d3e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019ea99f-cb7f-7d9f-90a2-88a0aca44289" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ea99f-cb7f-77cd-b331-892170041d3e" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019ea99f-cb7f-7d9f-90a2-88a0aca44289" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019ea99f-cb7f-7094-877c-7833521826ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ea99f-cb7f-77cd-b331-892170041d3e" xlink:to="loc_us-gaap_ProfitLoss_019ea99f-cb7f-7094-877c-7833521826ea" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019ea99f-cb7f-7051-ae26-56f319d8f5a6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ea99f-cb7f-77cd-b331-892170041d3e" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019ea99f-cb7f-7051-ae26-56f319d8f5a6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019ea99f-cb7f-7e96-9fc7-fc7f9640f930" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ea99f-cb7f-77cd-b331-892170041d3e" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019ea99f-cb7f-7e96-9fc7-fc7f9640f930" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_019ea99f-cb7f-7d88-814d-4850f8429142" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ea99f-cb7f-77cd-b331-892170041d3e" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_019ea99f-cb7f-7d88-814d-4850f8429142" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueOther_019ea99f-cb7f-77bc-9d87-e3c6fe18200d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ea99f-cb7f-77cd-b331-892170041d3e" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueOther_019ea99f-cb7f-77bc-9d87-e3c6fe18200d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPreferredStockCash_019ea99f-cb7f-745d-a630-ebc380194909" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsPreferredStockCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ea99f-cb7f-77cd-b331-892170041d3e" xlink:to="loc_us-gaap_DividendsPreferredStockCash_019ea99f-cb7f-745d-a630-ebc380194909" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestPeriodIncreaseDecrease_019f82d0-2cff-7015-aea2-62a164c1047b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MinorityInterestPeriodIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019ea99f-cb7f-77cd-b331-892170041d3e" xlink:to="loc_us-gaap_MinorityInterestPeriodIncreaseDecrease_019f82d0-2cff-7015-aea2-62a164c1047b" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019ea99f-cb7f-729e-8147-036b181c447e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/SummaryofBusinessSegmentDataScheduleofSegmentReportingInformationbySegmentDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#SummaryofBusinessSegmentDataScheduleofSegmentReportingInformationbySegmentDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/SummaryofBusinessSegmentDataScheduleofSegmentReportingInformationbySegmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cb7f-77a8-9a34-cbeed9e95932" 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_019ea99f-cb7f-7358-b6ec-e9cc8f6ac26d" 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_019ea99f-cb7f-77a8-9a34-cbeed9e95932" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ea99f-cb7f-7358-b6ec-e9cc8f6ac26d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019ea99f-cb7f-7937-9d38-52d76a1f6757" 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_019ea99f-cb7f-7358-b6ec-e9cc8f6ac26d" xlink:to="loc_srt_ConsolidationItemsAxis_019ea99f-cb7f-7937-9d38-52d76a1f6757" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ea99f-cb7f-7937-9d38-52d76a1f6757_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_019ea99f-cb7f-7937-9d38-52d76a1f6757" xlink:to="loc_srt_ConsolidationItemsDomain_019ea99f-cb7f-7937-9d38-52d76a1f6757_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ea99f-cb7f-7392-8fca-1c59c43db789" 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_019ea99f-cb7f-7937-9d38-52d76a1f6757" xlink:to="loc_srt_ConsolidationItemsDomain_019ea99f-cb7f-7392-8fca-1c59c43db789" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019ea99f-cb7f-71b9-a48b-ca1a8203dd4c" 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_019ea99f-cb7f-7392-8fca-1c59c43db789" xlink:to="loc_us-gaap_OperatingSegmentsMember_019ea99f-cb7f-71b9-a48b-ca1a8203dd4c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CorporateReconcilingItemsAndEliminationsMember_019ea99f-cb7f-7a14-9ee4-a5265cdb889a" xlink:href="ba-20260630.xsd#ba_CorporateReconcilingItemsAndEliminationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019ea99f-cb7f-7392-8fca-1c59c43db789" xlink:to="loc_ba_CorporateReconcilingItemsAndEliminationsMember_019ea99f-cb7f-7a14-9ee4-a5265cdb889a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019ea99f-cb7f-7623-8bb9-a27b2aabcd8a" 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_019ea99f-cb7f-7358-b6ec-e9cc8f6ac26d" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019ea99f-cb7f-7623-8bb9-a27b2aabcd8a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ea99f-cb7f-7623-8bb9-a27b2aabcd8a_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_019ea99f-cb7f-7623-8bb9-a27b2aabcd8a" xlink:to="loc_us-gaap_SegmentDomain_019ea99f-cb7f-7623-8bb9-a27b2aabcd8a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ea99f-cb7f-7ca1-8568-2dfc1a537b2f" 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_019ea99f-cb7f-7623-8bb9-a27b2aabcd8a" xlink:to="loc_us-gaap_SegmentDomain_019ea99f-cb7f-7ca1-8568-2dfc1a537b2f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommercialAirplanesSegmentMember_019ea99f-cb7f-7001-8e89-f05f20b7e0c0" xlink:href="ba-20260630.xsd#ba_CommercialAirplanesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cb7f-7ca1-8568-2dfc1a537b2f" xlink:to="loc_ba_CommercialAirplanesSegmentMember_019ea99f-cb7f-7001-8e89-f05f20b7e0c0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BoeingDefenseSpaceSecuritySegmentMember_019ea99f-cb7f-7276-9f17-4a726017515f" xlink:href="ba-20260630.xsd#ba_BoeingDefenseSpaceSecuritySegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cb7f-7ca1-8568-2dfc1a537b2f" xlink:to="loc_ba_BoeingDefenseSpaceSecuritySegmentMember_019ea99f-cb7f-7276-9f17-4a726017515f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_GlobalServicesMember_019ea99f-cb7f-75cd-84d5-5c65b3f1283a" xlink:href="ba-20260630.xsd#ba_GlobalServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cb7f-7ca1-8568-2dfc1a537b2f" xlink:to="loc_ba_GlobalServicesMember_019ea99f-cb7f-75cd-84d5-5c65b3f1283a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019ea99f-cb7f-794e-9aed-a9806dad7d08" 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_019ea99f-cb7f-77a8-9a34-cbeed9e95932" xlink:to="loc_us-gaap_Revenues_019ea99f-cb7f-794e-9aed-a9806dad7d08" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019ea99f-cb7f-74d6-85ab-7cdf67a52282" 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_SegmentReportingInformationLineItems_019ea99f-cb7f-77a8-9a34-cbeed9e95932" xlink:to="loc_us-gaap_OperatingIncomeLoss_019ea99f-cb7f-74d6-85ab-7cdf67a52282" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_OperatingIncomeLossExcludingUnallocatedPensionAndPostretirementAdjustments_019ea99f-cb7f-7492-96d2-7f33ffdf75c1" xlink:href="ba-20260630.xsd#ba_OperatingIncomeLossExcludingUnallocatedPensionAndPostretirementAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cb7f-77a8-9a34-cbeed9e95932" xlink:to="loc_ba_OperatingIncomeLossExcludingUnallocatedPensionAndPostretirementAdjustments_019ea99f-cb7f-7492-96d2-7f33ffdf75c1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_FASCASServiceCostAdjustment_019ea99f-cb7f-7de7-80e6-49fe5902396d" xlink:href="ba-20260630.xsd#ba_FASCASServiceCostAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cb7f-77a8-9a34-cbeed9e95932" xlink:to="loc_ba_FASCASServiceCostAdjustment_019ea99f-cb7f-7de7-80e6-49fe5902396d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019ea99f-cb7f-76f8-9b94-ccc7c7f8a490" 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_SegmentReportingInformationLineItems_019ea99f-cb7f-77a8-9a34-cbeed9e95932" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019ea99f-cb7f-76f8-9b94-ccc7c7f8a490" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDebtExpense_019ea99f-cb7f-7b5e-aca7-13be1f69f5d1" 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_SegmentReportingInformationLineItems_019ea99f-cb7f-77a8-9a34-cbeed9e95932" xlink:to="loc_us-gaap_InterestAndDebtExpense_019ea99f-cb7f-7b5e-aca7-13be1f69f5d1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019ea99f-cb7f-799d-88fe-ce21236b1902" 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_SegmentReportingInformationLineItems_019ea99f-cb7f-77a8-9a34-cbeed9e95932" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019ea99f-cb7f-799d-88fe-ce21236b1902" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019ea99f-cb7f-7d51-bd83-40e1a170fea4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cb7f-77a8-9a34-cbeed9e95932" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019ea99f-cb7f-7d51-bd83-40e1a170fea4" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019ea99f-cb7f-7551-a6b4-5d1c664af646" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cb7f-77a8-9a34-cbeed9e95932" xlink:to="loc_us-gaap_ProfitLoss_019ea99f-cb7f-7551-a6b4-5d1c664af646" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019ea99f-cb7f-7b77-84da-562ebe85de4d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cb7f-77a8-9a34-cbeed9e95932" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019ea99f-cb7f-7b77-84da-562ebe85de4d" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019ea99f-cb7f-78c5-8081-2a4316413a27" 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_SegmentReportingInformationLineItems_019ea99f-cb7f-77a8-9a34-cbeed9e95932" xlink:to="loc_us-gaap_NetIncomeLoss_019ea99f-cb7f-78c5-8081-2a4316413a27" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendsIncomeStatementImpact_019ea99f-cb7f-7190-b3bd-bf06194f0587" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockDividendsIncomeStatementImpact"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cb7f-77a8-9a34-cbeed9e95932" xlink:to="loc_us-gaap_PreferredStockDividendsIncomeStatementImpact_019ea99f-cb7f-7190-b3bd-bf06194f0587" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_019ea99f-cb7f-767b-96cf-a823d553eab4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cb7f-77a8-9a34-cbeed9e95932" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_019ea99f-cb7f-767b-96cf-a823d553eab4" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_019ea99f-cb7f-70fd-8098-ac320d78392d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cb7f-77a8-9a34-cbeed9e95932" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_019ea99f-cb7f-70fd-8098-ac320d78392d" xlink:type="arc" order="13"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/BasisofPresentationNarrativeDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#BasisofPresentationNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/BasisofPresentationNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ba_BasisOfPresentationDisclosureLineItems_019ea99f-cb7f-7924-8569-1f7d73387e3a" xlink:href="ba-20260630.xsd#ba_BasisOfPresentationDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BasisofPresentationDisclosureTable_019ea99f-cb7f-7eea-b386-97cb90668587" xlink:href="ba-20260630.xsd#ba_BasisofPresentationDisclosureTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ba_BasisOfPresentationDisclosureLineItems_019ea99f-cb7f-7924-8569-1f7d73387e3a" xlink:to="loc_ba_BasisofPresentationDisclosureTable_019ea99f-cb7f-7eea-b386-97cb90668587" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReportingUnitAxis_019ea99f-cb7f-7207-a770-f6a78c120c4e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReportingUnitAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ba_BasisofPresentationDisclosureTable_019ea99f-cb7f-7eea-b386-97cb90668587" xlink:to="loc_us-gaap_ReportingUnitAxis_019ea99f-cb7f-7207-a770-f6a78c120c4e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReportingUnitDomain_019ea99f-cb7f-7207-a770-f6a78c120c4e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReportingUnitDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ReportingUnitAxis_019ea99f-cb7f-7207-a770-f6a78c120c4e" xlink:to="loc_us-gaap_ReportingUnitDomain_019ea99f-cb7f-7207-a770-f6a78c120c4e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReportingUnitDomain_019ea99f-cb7f-758c-8cd8-f6f3c0d7652b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReportingUnitDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ReportingUnitAxis_019ea99f-cb7f-7207-a770-f6a78c120c4e" xlink:to="loc_us-gaap_ReportingUnitDomain_019ea99f-cb7f-758c-8cd8-f6f3c0d7652b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_MilitaryAircraftMember_019ea99f-cb7f-7e59-8324-3a25932f2acb" xlink:href="ba-20260630.xsd#ba_MilitaryAircraftMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReportingUnitDomain_019ea99f-cb7f-758c-8cd8-f6f3c0d7652b" xlink:to="loc_ba_MilitaryAircraftMember_019ea99f-cb7f-7e59-8324-3a25932f2acb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019ea99f-cb7f-73a8-8462-0583bd1c7c6c" 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_ba_BasisofPresentationDisclosureTable_019ea99f-cb7f-7eea-b386-97cb90668587" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019ea99f-cb7f-73a8-8462-0583bd1c7c6c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ea99f-cb7f-73a8-8462-0583bd1c7c6c_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_019ea99f-cb7f-73a8-8462-0583bd1c7c6c" xlink:to="loc_us-gaap_SegmentDomain_019ea99f-cb7f-73a8-8462-0583bd1c7c6c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ea99f-cb7f-7d61-a070-0aefa0857ac7" 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_019ea99f-cb7f-73a8-8462-0583bd1c7c6c" xlink:to="loc_us-gaap_SegmentDomain_019ea99f-cb7f-7d61-a070-0aefa0857ac7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BoeingDefenseSpaceSecuritySegmentMember_019ea99f-cb7f-710c-b308-e813b5e7a705" xlink:href="ba-20260630.xsd#ba_BoeingDefenseSpaceSecuritySegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cb7f-7d61-a070-0aefa0857ac7" xlink:to="loc_ba_BoeingDefenseSpaceSecuritySegmentMember_019ea99f-cb7f-710c-b308-e813b5e7a705" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019ea99f-cb7f-7651-8c68-3cf7ea4e0601" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_BasisOfPresentationDisclosureLineItems_019ea99f-cb7f-7924-8569-1f7d73387e3a" xlink:to="loc_us-gaap_Goodwill_019ea99f-cb7f-7651-8c68-3cf7ea4e0601" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/SpiritAcquisitionNarrativeDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#SpiritAcquisitionNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/SpiritAcquisitionNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019f8306-d88f-7334-8bc0-8fc41b859be5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ea99f-cb7f-73e6-b836-cc8da7256206" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8306-d88f-7334-8bc0-8fc41b859be5" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ea99f-cb7f-73e6-b836-cc8da7256206" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019f8306-d88f-7a11-8eb3-ac0c34198696" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ea99f-cb7f-73e6-b836-cc8da7256206" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019f8306-d88f-7a11-8eb3-ac0c34198696" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8306-d88f-7a11-8eb3-ac0c34198696_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019f8306-d88f-7a11-8eb3-ac0c34198696" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8306-d88f-7a11-8eb3-ac0c34198696_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8306-d88f-737e-9f37-18daf0d4c13a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019f8306-d88f-7a11-8eb3-ac0c34198696" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8306-d88f-737e-9f37-18daf0d4c13a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_SpiritAeroSystemsHoldingsInc.Member_019f8306-d88f-71de-a472-051ddc2f6c84" xlink:href="ba-20260630.xsd#ba_SpiritAeroSystemsHoldingsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019f8306-d88f-737e-9f37-18daf0d4c13a" xlink:to="loc_ba_SpiritAeroSystemsHoldingsInc.Member_019f8306-d88f-71de-a472-051ddc2f6c84" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8307-7bce-7791-b7c7-f8b93f71a83f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ea99f-cb7f-73e6-b836-cc8da7256206" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8307-7bce-7791-b7c7-f8b93f71a83f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8307-7bce-7791-b7c7-f8b93f71a83f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8307-7bce-7791-b7c7-f8b93f71a83f" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8307-7bce-7791-b7c7-f8b93f71a83f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8307-7bce-7d2a-8fa3-6e06e7a826ac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8307-7bce-7791-b7c7-f8b93f71a83f" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8307-7bce-7d2a-8fa3-6e06e7a826ac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_019f8307-7bce-7a58-8c1c-8b153826294b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8307-7bce-7d2a-8fa3-6e06e7a826ac" xlink:to="loc_us-gaap_CustomerRelationshipsMember_019f8307-7bce-7a58-8c1c-8b153826294b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InProcessResearchAndDevelopmentMember_019f8307-7bce-75fa-a830-3fff11f6e7e7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InProcessResearchAndDevelopmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8307-7bce-7d2a-8fa3-6e06e7a826ac" xlink:to="loc_us-gaap_InProcessResearchAndDevelopmentMember_019f8307-7bce-75fa-a830-3fff11f6e7e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019f8306-d88f-7e45-be36-ab7147d6091e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8306-d88f-7334-8bc0-8fc41b859be5" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019f8306-d88f-7e45-be36-ab7147d6091e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019f8307-7bce-7bc2-9090-e9eb569b35a6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8306-d88f-7334-8bc0-8fc41b859be5" xlink:to="loc_us-gaap_Goodwill_019f8307-7bce-7bc2-9090-e9eb569b35a6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_019f8309-f144-78a9-8fa6-729dd167719d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinitelivedIntangibleAssetsAcquired1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8306-d88f-7334-8bc0-8fc41b859be5" xlink:to="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_019f8309-f144-78a9-8fa6-729dd167719d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019f8307-7bce-787e-8e81-e2e5fe8f9a32" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8306-d88f-7334-8bc0-8fc41b859be5" xlink:to="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_019f8307-7bce-787e-8e81-e2e5fe8f9a32" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BusinessCombinationRecognizedLiabilityAssumedAccruedLiability_019f8307-7bce-7d54-876f-b7b29574293e" xlink:href="ba-20260630.xsd#ba_BusinessCombinationRecognizedLiabilityAssumedAccruedLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8306-d88f-7334-8bc0-8fc41b859be5" xlink:to="loc_ba_BusinessCombinationRecognizedLiabilityAssumedAccruedLiability_019f8307-7bce-7d54-876f-b7b29574293e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BusinessCombinationFinalizedPurchasePriceAllocationDuration_019f8307-d16c-7fbb-836d-751bb78cfd1b" xlink:href="ba-20260630.xsd#ba_BusinessCombinationFinalizedPurchasePriceAllocationDuration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019f8306-d88f-7334-8bc0-8fc41b859be5" xlink:to="loc_ba_BusinessCombinationFinalizedPurchasePriceAllocationDuration_019f8307-d16c-7fbb-836d-751bb78cfd1b" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/SpiritAcquisitionScheduleofBusinessCombinationDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#SpiritAcquisitionScheduleofBusinessCombinationDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/SpiritAcquisitionScheduleofBusinessCombinationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019ea99f-cc26-7a0c-afd0-12e3461dfb04" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ea99f-cc26-7d17-9f87-1dc1cd196a04" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ea99f-cc26-7a0c-afd0-12e3461dfb04" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ea99f-cc26-7d17-9f87-1dc1cd196a04" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019ea99f-cc26-7be9-a212-498ed1a635b0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ea99f-cc26-7d17-9f87-1dc1cd196a04" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019ea99f-cc26-7be9-a212-498ed1a635b0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-7be9-a212-498ed1a635b0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019ea99f-cc26-7be9-a212-498ed1a635b0" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-7be9-a212-498ed1a635b0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-7194-aefc-f57944351a9e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019ea99f-cc26-7be9-a212-498ed1a635b0" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-7194-aefc-f57944351a9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_SpiritAeroSystemsHoldingsInc.Member_019ea99f-cc26-7645-9a5f-38349ddcb622" xlink:href="ba-20260630.xsd#ba_SpiritAeroSystemsHoldingsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-7194-aefc-f57944351a9e" xlink:to="loc_ba_SpiritAeroSystemsHoldingsInc.Member_019ea99f-cc26-7645-9a5f-38349ddcb622" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_019ea99f-cc26-74b9-9c74-c82a698723e4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityInterestIssuedOrIssuableByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ea99f-cc26-7d17-9f87-1dc1cd196a04" xlink:to="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_019ea99f-cc26-74b9-9c74-c82a698723e4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_019ea99f-cc26-74b9-9c74-c82a698723e4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityInterestIssuedOrIssuableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_019ea99f-cc26-74b9-9c74-c82a698723e4" xlink:to="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_019ea99f-cc26-74b9-9c74-c82a698723e4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_019ea99f-cc26-7b6f-8c3e-53cfb20db68b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityInterestIssuedOrIssuableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_019ea99f-cc26-74b9-9c74-c82a698723e4" xlink:to="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_019ea99f-cc26-7b6f-8c3e-53cfb20db68b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BoeingCommonStockExchangedForSpiritCommonStockMember_019ea99f-cc26-7c61-ba84-9bc1518ed0be" xlink:href="ba-20260630.xsd#ba_BoeingCommonStockExchangedForSpiritCommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_019ea99f-cc26-7b6f-8c3e-53cfb20db68b" xlink:to="loc_ba_BoeingCommonStockExchangedForSpiritCommonStockMember_019ea99f-cc26-7c61-ba84-9bc1518ed0be" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_PremiumOnAssumedExchangeableNotesMember_019ea99f-cc26-735a-9884-f2bf714520ef" xlink:href="ba-20260630.xsd#ba_PremiumOnAssumedExchangeableNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_019ea99f-cc26-7b6f-8c3e-53cfb20db68b" xlink:to="loc_ba_PremiumOnAssumedExchangeableNotesMember_019ea99f-cc26-735a-9884-f2bf714520ef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_ExchangeOfSpiritShareBasedAwardsMember_019ea99f-cc26-72ae-8f43-5a000b788f35" xlink:href="ba-20260630.xsd#ba_ExchangeOfSpiritShareBasedAwardsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_019ea99f-cc26-7b6f-8c3e-53cfb20db68b" xlink:to="loc_ba_ExchangeOfSpiritShareBasedAwardsMember_019ea99f-cc26-72ae-8f43-5a000b788f35" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContingentConsiderationByTypeAxis_019ea99f-cc26-759c-9a1a-27b1ccbcc9d8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContingentConsiderationByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ea99f-cc26-7d17-9f87-1dc1cd196a04" xlink:to="loc_us-gaap_ContingentConsiderationByTypeAxis_019ea99f-cc26-759c-9a1a-27b1ccbcc9d8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContingentConsiderationTypeDomain_019ea99f-cc26-759c-9a1a-27b1ccbcc9d8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContingentConsiderationTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ContingentConsiderationByTypeAxis_019ea99f-cc26-759c-9a1a-27b1ccbcc9d8" xlink:to="loc_us-gaap_ContingentConsiderationTypeDomain_019ea99f-cc26-759c-9a1a-27b1ccbcc9d8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContingentConsiderationTypeDomain_019ea99f-cc26-7be1-b8b8-79383775a146" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContingentConsiderationTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ContingentConsiderationByTypeAxis_019ea99f-cc26-759c-9a1a-27b1ccbcc9d8" xlink:to="loc_us-gaap_ContingentConsiderationTypeDomain_019ea99f-cc26-7be1-b8b8-79383775a146" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_SettlementOfLoansAdvanceAndOtherPaymentsWithSpiritMember_019ea99f-cc26-7466-ae45-0e7b1da16217" xlink:href="ba-20260630.xsd#ba_SettlementOfLoansAdvanceAndOtherPaymentsWithSpiritMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContingentConsiderationTypeDomain_019ea99f-cc26-7be1-b8b8-79383775a146" xlink:to="loc_ba_SettlementOfLoansAdvanceAndOtherPaymentsWithSpiritMember_019ea99f-cc26-7466-ae45-0e7b1da16217" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_DebtRepaidOnSpiritsBehalfMember_019ea99f-cc26-7e7d-85db-b607057f2125" xlink:href="ba-20260630.xsd#ba_DebtRepaidOnSpiritsBehalfMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContingentConsiderationTypeDomain_019ea99f-cc26-7be1-b8b8-79383775a146" xlink:to="loc_ba_DebtRepaidOnSpiritsBehalfMember_019ea99f-cc26-7e7d-85db-b607057f2125" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_019ea99f-cc26-7336-8337-9d64ba98fca7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ea99f-cc26-7a0c-afd0-12e3461dfb04" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuable_019ea99f-cc26-7336-8337-9d64ba98fca7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred_019ea99f-cc26-7e83-a54f-02658b8b90f7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ea99f-cc26-7a0c-afd0-12e3461dfb04" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferredLiabilitiesIncurred_019ea99f-cc26-7e83-a54f-02658b8b90f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019ea99f-cc26-7d8f-b835-bf5358fbe5e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ea99f-cc26-7a0c-afd0-12e3461dfb04" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_019ea99f-cc26-7d8f-b835-bf5358fbe5e3" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/SpiritAcquisitionScheduleofBusinessCombinationRecognizedAssetAcquiredandLiabilityAssumedDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#SpiritAcquisitionScheduleofBusinessCombinationRecognizedAssetAcquiredandLiabilityAssumedDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/SpiritAcquisitionScheduleofBusinessCombinationRecognizedAssetAcquiredandLiabilityAssumedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019ea99f-cc26-73b8-9dac-df3b5523d8d3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ea99f-cc26-757c-bcd1-ffd1f70bced9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ea99f-cc26-73b8-9dac-df3b5523d8d3" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ea99f-cc26-757c-bcd1-ffd1f70bced9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019ea99f-cc26-7d33-bfd4-1bd5e8e43b5a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ea99f-cc26-757c-bcd1-ffd1f70bced9" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019ea99f-cc26-7d33-bfd4-1bd5e8e43b5a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-7d33-bfd4-1bd5e8e43b5a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019ea99f-cc26-7d33-bfd4-1bd5e8e43b5a" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-7d33-bfd4-1bd5e8e43b5a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-7677-832f-19d0d956ca43" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019ea99f-cc26-7d33-bfd4-1bd5e8e43b5a" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-7677-832f-19d0d956ca43" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_SpiritAeroSystemsHoldingsInc.Member_019ea99f-cc26-772f-983e-0099a9e73539" xlink:href="ba-20260630.xsd#ba_SpiritAeroSystemsHoldingsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-7677-832f-19d0d956ca43" xlink:to="loc_ba_SpiritAeroSystemsHoldingsInc.Member_019ea99f-cc26-772f-983e-0099a9e73539" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8306-2455-759e-97c8-9c9e08b764b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ea99f-cc26-757c-bcd1-ffd1f70bced9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8306-2455-759e-97c8-9c9e08b764b3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8306-2455-759e-97c8-9c9e08b764b3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8306-2455-759e-97c8-9c9e08b764b3" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8306-2455-759e-97c8-9c9e08b764b3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8306-2455-7753-a753-1bca069bc8a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019f8306-2455-759e-97c8-9c9e08b764b3" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8306-2455-7753-a753-1bca069bc8a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InProcessResearchAndDevelopmentMember_019f8306-2455-7226-b9e4-8b073baec9c1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InProcessResearchAndDevelopmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019f8306-2455-7753-a753-1bca069bc8a8" xlink:to="loc_us-gaap_InProcessResearchAndDevelopmentMember_019f8306-2455-7226-b9e4-8b073baec9c1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BusinessCombinationPreliminaryAmountAbstract_019ea99f-cc26-7cb0-b9a1-cb4bbc9b2822" xlink:href="ba-20260630.xsd#ba_BusinessCombinationPreliminaryAmountAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ea99f-cc26-73b8-9dac-df3b5523d8d3" xlink:to="loc_ba_BusinessCombinationPreliminaryAmountAbstract_019ea99f-cc26-7cb0-b9a1-cb4bbc9b2822" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_019ea99f-cc26-7e46-8c71-8e751a1e8972" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_BusinessCombinationPreliminaryAmountAbstract_019ea99f-cc26-7cb0-b9a1-cb4bbc9b2822" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_019ea99f-cc26-7e46-8c71-8e751a1e8972" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_019ea99f-cc26-7123-b676-99a6656cb6f9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_BusinessCombinationPreliminaryAmountAbstract_019ea99f-cc26-7cb0-b9a1-cb4bbc9b2822" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_019ea99f-cc26-7123-b676-99a6656cb6f9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BusinessCombinationRecognizedAssetAcquiredUnbilledReceivableCurrent_019ea99f-cc26-79c9-a57d-5b392296defa" xlink:href="ba-20260630.xsd#ba_BusinessCombinationRecognizedAssetAcquiredUnbilledReceivableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_BusinessCombinationPreliminaryAmountAbstract_019ea99f-cc26-7cb0-b9a1-cb4bbc9b2822" xlink:to="loc_ba_BusinessCombinationRecognizedAssetAcquiredUnbilledReceivableCurrent_019ea99f-cc26-79c9-a57d-5b392296defa" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_019ea99f-cc26-74d0-9bbe-351a8fd28c31" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_BusinessCombinationPreliminaryAmountAbstract_019ea99f-cc26-7cb0-b9a1-cb4bbc9b2822" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_019ea99f-cc26-74d0-9bbe-351a8fd28c31" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_019ea99f-cc26-71f2-93a2-825271f4bdc5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_BusinessCombinationPreliminaryAmountAbstract_019ea99f-cc26-7cb0-b9a1-cb4bbc9b2822" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_019ea99f-cc26-71f2-93a2-825271f4bdc5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019ea99f-cc26-73fa-9097-9ac5d415f32b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_BusinessCombinationPreliminaryAmountAbstract_019ea99f-cc26-7cb0-b9a1-cb4bbc9b2822" xlink:to="loc_us-gaap_Goodwill_019ea99f-cc26-73fa-9097-9ac5d415f32b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019ea99f-cc26-7a98-99df-d4fda49b97af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_BusinessCombinationPreliminaryAmountAbstract_019ea99f-cc26-7cb0-b9a1-cb4bbc9b2822" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_019ea99f-cc26-7a98-99df-d4fda49b97af" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_019ea99f-cc26-7dac-af74-54f612a8a540" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_BusinessCombinationPreliminaryAmountAbstract_019ea99f-cc26-7cb0-b9a1-cb4bbc9b2822" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_019ea99f-cc26-7dac-af74-54f612a8a540" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BusinessCombinationRecognizedLiabilityAssumedAccountsPayable_019ea99f-cc26-7ba3-994f-03054c163b8e" xlink:href="ba-20260630.xsd#ba_BusinessCombinationRecognizedLiabilityAssumedAccountsPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_BusinessCombinationPreliminaryAmountAbstract_019ea99f-cc26-7cb0-b9a1-cb4bbc9b2822" xlink:to="loc_ba_BusinessCombinationRecognizedLiabilityAssumedAccountsPayable_019ea99f-cc26-7ba3-994f-03054c163b8e" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_019ea99f-cc26-751b-a9b1-927a7034c2db" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_BusinessCombinationPreliminaryAmountAbstract_019ea99f-cc26-7cb0-b9a1-cb4bbc9b2822" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_019ea99f-cc26-751b-a9b1-927a7034c2db" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BusinessCombinationRecognizedLiabilityAssumedAdvancesAndProgressBillingsLiability_019ea99f-cc26-796c-a62c-e7c3080387af" xlink:href="ba-20260630.xsd#ba_BusinessCombinationRecognizedLiabilityAssumedAdvancesAndProgressBillingsLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_BusinessCombinationPreliminaryAmountAbstract_019ea99f-cc26-7cb0-b9a1-cb4bbc9b2822" xlink:to="loc_ba_BusinessCombinationRecognizedLiabilityAssumedAdvancesAndProgressBillingsLiability_019ea99f-cc26-796c-a62c-e7c3080387af" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BusinessCombinationRecognizedLiabilityAssumedShortTermAndLongTermDebtCurrent_019ea99f-cc26-75f9-9913-179c886c5c2b" xlink:href="ba-20260630.xsd#ba_BusinessCombinationRecognizedLiabilityAssumedShortTermAndLongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_BusinessCombinationPreliminaryAmountAbstract_019ea99f-cc26-7cb0-b9a1-cb4bbc9b2822" xlink:to="loc_ba_BusinessCombinationRecognizedLiabilityAssumedShortTermAndLongTermDebtCurrent_019ea99f-cc26-75f9-9913-179c886c5c2b" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_019ea99f-cc26-7822-a96a-83a3a074a03c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_BusinessCombinationPreliminaryAmountAbstract_019ea99f-cc26-7cb0-b9a1-cb4bbc9b2822" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_019ea99f-cc26-7822-a96a-83a3a074a03c" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt_019ea99f-cc26-7003-84e7-ed46877fe591" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_BusinessCombinationPreliminaryAmountAbstract_019ea99f-cc26-7cb0-b9a1-cb4bbc9b2822" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt_019ea99f-cc26-7003-84e7-ed46877fe591" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BusinessCombinationRecognizedAssetAcquiredAndLiabilityAssumedOther_019ea99f-cc26-765c-80d4-4382b646bf50" xlink:href="ba-20260630.xsd#ba_BusinessCombinationRecognizedAssetAcquiredAndLiabilityAssumedOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_BusinessCombinationPreliminaryAmountAbstract_019ea99f-cc26-7cb0-b9a1-cb4bbc9b2822" xlink:to="loc_ba_BusinessCombinationRecognizedAssetAcquiredAndLiabilityAssumedOther_019ea99f-cc26-765c-80d4-4382b646bf50" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019ea99f-cc26-7483-b397-dbf97e03fba8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_BusinessCombinationPreliminaryAmountAbstract_019ea99f-cc26-7cb0-b9a1-cb4bbc9b2822" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_019ea99f-cc26-7483-b397-dbf97e03fba8" xlink:type="arc" order="16"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/SpiritAcquisitionPresentValueofFutureInsuranceProfitsExpectedAmortizationDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#SpiritAcquisitionPresentValueofFutureInsuranceProfitsExpectedAmortizationDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/SpiritAcquisitionPresentValueofFutureInsuranceProfitsExpectedAmortizationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_019ea99f-cc26-786d-aeb8-6e727d565648" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ea99f-cc26-7354-90fb-0916ce2a295e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ea99f-cc26-786d-aeb8-6e727d565648" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ea99f-cc26-7354-90fb-0916ce2a295e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019ea99f-cc26-7497-8b8a-9cead2332ac0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_019ea99f-cc26-7354-90fb-0916ce2a295e" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019ea99f-cc26-7497-8b8a-9cead2332ac0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-7497-8b8a-9cead2332ac0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019ea99f-cc26-7497-8b8a-9cead2332ac0" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-7497-8b8a-9cead2332ac0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-7cbb-ac34-60328461c666" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019ea99f-cc26-7497-8b8a-9cead2332ac0" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-7cbb-ac34-60328461c666" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_SpiritAeroSystemsHoldingsInc.Member_019ea99f-cc26-7255-ad30-7ab337df7f20" xlink:href="ba-20260630.xsd#ba_SpiritAeroSystemsHoldingsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-7cbb-ac34-60328461c666" xlink:to="loc_ba_SpiritAeroSystemsHoldingsInc.Member_019ea99f-cc26-7255-ad30-7ab337df7f20" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationAbstract_019ea99f-cc26-7162-91a7-f8a41775956d" xlink:href="ba-20260630.xsd#ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_019ea99f-cc26-786d-aeb8-6e727d565648" xlink:to="loc_ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationAbstract_019ea99f-cc26-7162-91a7-f8a41775956d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationYearOne_019ea99f-cc26-70ae-8dce-b1e53cff361c" xlink:href="ba-20260630.xsd#ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationYearOne"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationAbstract_019ea99f-cc26-7162-91a7-f8a41775956d" xlink:to="loc_ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationYearOne_019ea99f-cc26-70ae-8dce-b1e53cff361c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationYearTwo_019ea99f-cc26-7eb6-a909-e9a23df6624a" xlink:href="ba-20260630.xsd#ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationYearTwo"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationAbstract_019ea99f-cc26-7162-91a7-f8a41775956d" xlink:to="loc_ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationYearTwo_019ea99f-cc26-7eb6-a909-e9a23df6624a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationYearThree_019ea99f-cc26-791f-897f-e1e07eeeee8f" xlink:href="ba-20260630.xsd#ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationYearThree"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationAbstract_019ea99f-cc26-7162-91a7-f8a41775956d" xlink:to="loc_ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationYearThree_019ea99f-cc26-791f-897f-e1e07eeeee8f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationYearFour_019ea99f-cc26-7459-a62f-443fd0bef023" xlink:href="ba-20260630.xsd#ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationYearFour"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationAbstract_019ea99f-cc26-7162-91a7-f8a41775956d" xlink:to="loc_ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationYearFour_019ea99f-cc26-7459-a62f-443fd0bef023" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationYearFive_019ea99f-cc26-7ba8-b0e1-340dcdebe1c3" xlink:href="ba-20260630.xsd#ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationYearFive"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationAbstract_019ea99f-cc26-7162-91a7-f8a41775956d" xlink:to="loc_ba_PresentValueOfEstimatedRevenueFromExpectedAmortizationYearFive_019ea99f-cc26-7ba8-b0e1-340dcdebe1c3" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/EarningsPerShareScheduleofWeightedAverageNumberofSharesOutstandingExcludedfromtheComputationofDilutedEarningsPerShareDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#EarningsPerShareScheduleofWeightedAverageNumberofSharesOutstandingExcludedfromtheComputationofDilutedEarningsPerShareDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/EarningsPerShareScheduleofWeightedAverageNumberofSharesOutstandingExcludedfromtheComputationofDilutedEarningsPerShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019ea99f-cc26-766c-92c7-1200ee462a76" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019ea99f-cc26-7f1e-9e46-3573d3711602" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019ea99f-cc26-766c-92c7-1200ee462a76" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019ea99f-cc26-7f1e-9e46-3573d3711602" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019ea99f-cc26-717f-a5f7-bc5a1a9e0b32" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019ea99f-cc26-7f1e-9e46-3573d3711602" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019ea99f-cc26-717f-a5f7-bc5a1a9e0b32" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019ea99f-cc26-717f-a5f7-bc5a1a9e0b32_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019ea99f-cc26-717f-a5f7-bc5a1a9e0b32" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019ea99f-cc26-717f-a5f7-bc5a1a9e0b32_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019ea99f-cc26-70d6-9cf2-f62ce0f305bb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019ea99f-cc26-717f-a5f7-bc5a1a9e0b32" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019ea99f-cc26-70d6-9cf2-f62ce0f305bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_019ea99f-cc26-7c07-a0ab-7665dfd00009" 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_AntidilutiveSecuritiesNameDomain_019ea99f-cc26-70d6-9cf2-f62ce0f305bb" xlink:to="loc_us-gaap_PerformanceSharesMember_019ea99f-cc26-7c07-a0ab-7665dfd00009" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019ea99f-cc26-7de6-a836-cfcb7437d655" 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_AntidilutiveSecuritiesNameDomain_019ea99f-cc26-70d6-9cf2-f62ce0f305bb" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019ea99f-cc26-7de6-a836-cfcb7437d655" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_019ea99f-cc26-7457-b129-fedb60a82305" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019ea99f-cc26-70d6-9cf2-f62ce0f305bb" xlink:to="loc_us-gaap_EmployeeStockOptionMember_019ea99f-cc26-7457-b129-fedb60a82305" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AntidilutiveOrPerformanceConditionNotMetAxis_019ea99f-cc26-70b8-87d4-e1c0c7f06baf" xlink:href="ba-20260630.xsd#ba_AntidilutiveOrPerformanceConditionNotMetAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019ea99f-cc26-7f1e-9e46-3573d3711602" xlink:to="loc_ba_AntidilutiveOrPerformanceConditionNotMetAxis_019ea99f-cc26-70b8-87d4-e1c0c7f06baf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AntidilutiveOrPerformanceConditionNotMetDomain_019ea99f-cc26-70b8-87d4-e1c0c7f06baf_default" xlink:href="ba-20260630.xsd#ba_AntidilutiveOrPerformanceConditionNotMetDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_ba_AntidilutiveOrPerformanceConditionNotMetAxis_019ea99f-cc26-70b8-87d4-e1c0c7f06baf" xlink:to="loc_ba_AntidilutiveOrPerformanceConditionNotMetDomain_019ea99f-cc26-70b8-87d4-e1c0c7f06baf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AntidilutiveOrPerformanceConditionNotMetDomain_019ea99f-cc26-7b64-8fd1-aa64b29df043" xlink:href="ba-20260630.xsd#ba_AntidilutiveOrPerformanceConditionNotMetDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_ba_AntidilutiveOrPerformanceConditionNotMetAxis_019ea99f-cc26-70b8-87d4-e1c0c7f06baf" xlink:to="loc_ba_AntidilutiveOrPerformanceConditionNotMetDomain_019ea99f-cc26-7b64-8fd1-aa64b29df043" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AntidilutiveOrPerformanceConditionNotMetMember_019ea99f-cc26-760a-a3a4-35b76099ece5" xlink:href="ba-20260630.xsd#ba_AntidilutiveOrPerformanceConditionNotMetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_AntidilutiveOrPerformanceConditionNotMetDomain_019ea99f-cc26-7b64-8fd1-aa64b29df043" xlink:to="loc_ba_AntidilutiveOrPerformanceConditionNotMetMember_019ea99f-cc26-760a-a3a4-35b76099ece5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019ea99f-cc26-741f-b01c-3acd19958e44" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019ea99f-cc26-766c-92c7-1200ee462a76" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019ea99f-cc26-741f-b01c-3acd19958e44" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/EarningsPerShareNarrativeDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#EarningsPerShareNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/EarningsPerShareNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019ea99f-cc26-7cf2-a19d-47544a25c79a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019ea99f-cc26-72b4-be14-f4a07b9bfb53" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019ea99f-cc26-7cf2-a19d-47544a25c79a" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019ea99f-cc26-72b4-be14-f4a07b9bfb53" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019ea99f-cc26-7453-b792-980a255091e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019ea99f-cc26-72b4-be14-f4a07b9bfb53" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019ea99f-cc26-7453-b792-980a255091e1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019ea99f-cc26-7453-b792-980a255091e1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019ea99f-cc26-7453-b792-980a255091e1" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019ea99f-cc26-7453-b792-980a255091e1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019ea99f-cc26-7d49-934f-79109c26f243" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019ea99f-cc26-7453-b792-980a255091e1" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019ea99f-cc26-7d49-934f-79109c26f243" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AntidilutiveDueToNetLossMember_019ea99f-cc26-7184-9127-93ef76492c89" xlink:href="ba-20260630.xsd#ba_AntidilutiveDueToNetLossMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019ea99f-cc26-7d49-934f-79109c26f243" xlink:to="loc_ba_AntidilutiveDueToNetLossMember_019ea99f-cc26-7184-9127-93ef76492c89" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019ea99f-cc26-7d73-9ce5-fdeb0f2c78bc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_019ea99f-cc26-7cf2-a19d-47544a25c79a" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019ea99f-cc26-7d73-9ce5-fdeb0f2c78bc" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/AllowancesforLossesonFinancialAssetsScheduleofFinancialAssetsAllowanceforCreditLossDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#AllowancesforLossesonFinancialAssetsScheduleofFinancialAssetsAllowanceforCreditLossDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/AllowancesforLossesonFinancialAssetsScheduleofFinancialAssetsAllowanceforCreditLossDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforLossesonFinancialAssetsLineItems_019ea99f-cc26-7b4c-aad8-b4dfe45286a5" xlink:href="ba-20260630.xsd#ba_AllowanceforLossesonFinancialAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforLossesonFinancialAssetsTable_019ea99f-cc26-7cc6-844a-4c0b9a06000d" xlink:href="ba-20260630.xsd#ba_AllowanceforLossesonFinancialAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ba_AllowanceforLossesonFinancialAssetsLineItems_019ea99f-cc26-7b4c-aad8-b4dfe45286a5" xlink:to="loc_ba_AllowanceforLossesonFinancialAssetsTable_019ea99f-cc26-7cc6-844a-4c0b9a06000d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SfpLocationActivityAccrualAxis_019ea99f-cc26-7e53-8290-a8c6858e2944" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SfpLocationActivityAccrualAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ba_AllowanceforLossesonFinancialAssetsTable_019ea99f-cc26-7cc6-844a-4c0b9a06000d" xlink:to="loc_us-gaap_SfpLocationActivityAccrualAxis_019ea99f-cc26-7e53-8290-a8c6858e2944" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfFinancialPositionLocationBalanceAxis_019ea99f-cc26-7660-9343-308a1c554179" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfFinancialPositionLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ba_AllowanceforLossesonFinancialAssetsTable_019ea99f-cc26-7cc6-844a-4c0b9a06000d" xlink:to="loc_us-gaap_StatementOfFinancialPositionLocationBalanceAxis_019ea99f-cc26-7660-9343-308a1c554179" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_AllowanceforLossesonFinancialAssetsLineItems_019ea99f-cc26-7b4c-aad8-b4dfe45286a5" xlink:to="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_019ea99f-cc26-7a3e-b5b5-4e713d7b5070" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_019ea99f-cc26-7a3e-b5b5-4e713d7b5070" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss_019ea99f-cc26-7d74-bd6e-d18f206707f7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss_019ea99f-cc26-7d74-bd6e-d18f206707f7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforCreditLoss_019ea99f-cc26-72ce-9a58-651a1b2377c1" xlink:href="ba-20260630.xsd#ba_AllowanceforCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AllowanceforCreditLoss_019ea99f-cc26-72ce-9a58-651a1b2377c1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019ea99f-cc26-7012-9f37-450baa24f43d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019ea99f-cc26-7012-9f37-450baa24f43d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForDoubtfulAccounts_019ea99f-cc26-79ff-980c-514d4516a908" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForDoubtfulAccounts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_ProvisionForDoubtfulAccounts_019ea99f-cc26-79ff-980c-514d4516a908" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetCreditLossExpense_019ea99f-cc26-780f-bce4-94f63e7fae17" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerAssetCreditLossExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_ContractWithCustomerAssetCreditLossExpense_019ea99f-cc26-780f-bce4-94f63e7fae17" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceForCreditLossExpenseReversal_019ea99f-cc26-7244-bbaf-b4aca7345f93" xlink:href="ba-20260630.xsd#ba_AllowanceForCreditLossExpenseReversal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AllowanceForCreditLossExpenseReversal_019ea99f-cc26-7244-bbaf-b4aca7345f93" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLossesExpensed_019ea99f-cc26-7dcc-a0c2-68c6bc596587" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForLoanLossesExpensed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_ProvisionForLoanLossesExpensed_019ea99f-cc26-7dcc-a0c2-68c6bc596587" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs_019ea99f-cc26-7a6a-ae96-5f020cccc73f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs_019ea99f-cc26-7a6a-ae96-5f020cccc73f" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforCreditLossWriteoff_019ea99f-cc26-7114-90a8-211debbd2d23" xlink:href="ba-20260630.xsd#ba_AllowanceforCreditLossWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AllowanceforCreditLossWriteoff_019ea99f-cc26-7114-90a8-211debbd2d23" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableRecoveries_019ea99f-cc26-75b1-b983-9e5795775feb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableRecoveries"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableRecoveries_019ea99f-cc26-75b1-b983-9e5795775feb" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceForCreditLossRecoveries_019ea99f-cc26-7e40-bbac-b37646dabedd" xlink:href="ba-20260630.xsd#ba_AllowanceForCreditLossRecoveries"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AllowanceForCreditLossRecoveries_019ea99f-cc26-7e40-bbac-b37646dabedd" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AccountsReceivableAllowanceForCreditLossOther_019f1ec1-2a8e-765e-a88e-85825f83e447" xlink:href="ba-20260630.xsd#ba_AccountsReceivableAllowanceForCreditLossOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AccountsReceivableAllowanceForCreditLossOther_019f1ec1-2a8e-765e-a88e-85825f83e447" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_019ea99f-cc26-72e6-8fcf-75d7620b0394" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss_019ea99f-cc26-7ef4-b7b6-3f8cb98ba504" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforCreditLoss_019ea99f-cc26-7800-99cb-419eed18b82d" xlink:href="ba-20260630.xsd#ba_AllowanceforCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019ea99f-cc26-76ea-8415-d62bf7a8130a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/AllowancesforLossesonFinancialAssetsScheduleofFinancialAssetsAllowanceforCreditLossDetails_1" xlink:type="simple" xlink:href="ba-20260630.xsd#AllowancesforLossesonFinancialAssetsScheduleofFinancialAssetsAllowanceforCreditLossDetails_1"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/AllowancesforLossesonFinancialAssetsScheduleofFinancialAssetsAllowanceforCreditLossDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforLossesonFinancialAssetsLineItems_019ea99f-cc26-7b4c-aad8-b4dfe45286a5" xlink:href="ba-20260630.xsd#ba_AllowanceforLossesonFinancialAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforLossesonFinancialAssetsTable_019ea99f-cc26-7cc6-844a-4c0b9a06000d" xlink:href="ba-20260630.xsd#ba_AllowanceforLossesonFinancialAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ba_AllowanceforLossesonFinancialAssetsLineItems_019ea99f-cc26-7b4c-aad8-b4dfe45286a5" xlink:to="loc_ba_AllowanceforLossesonFinancialAssetsTable_019ea99f-cc26-7cc6-844a-4c0b9a06000d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_AllowanceforLossesonFinancialAssetsLineItems_019ea99f-cc26-7b4c-aad8-b4dfe45286a5" xlink:to="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_019ea99f-cc26-7a3e-b5b5-4e713d7b5070" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_019ea99f-cc26-7a3e-b5b5-4e713d7b5070" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss_019ea99f-cc26-7d74-bd6e-d18f206707f7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss_019ea99f-cc26-7d74-bd6e-d18f206707f7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforCreditLoss_019ea99f-cc26-72ce-9a58-651a1b2377c1" xlink:href="ba-20260630.xsd#ba_AllowanceforCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AllowanceforCreditLoss_019ea99f-cc26-72ce-9a58-651a1b2377c1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019ea99f-cc26-7012-9f37-450baa24f43d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019ea99f-cc26-7012-9f37-450baa24f43d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForDoubtfulAccounts_019ea99f-cc26-79ff-980c-514d4516a908" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForDoubtfulAccounts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_ProvisionForDoubtfulAccounts_019ea99f-cc26-79ff-980c-514d4516a908" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetCreditLossExpense_019ea99f-cc26-780f-bce4-94f63e7fae17" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerAssetCreditLossExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_ContractWithCustomerAssetCreditLossExpense_019ea99f-cc26-780f-bce4-94f63e7fae17" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceForCreditLossExpenseReversal_019ea99f-cc26-7244-bbaf-b4aca7345f93" xlink:href="ba-20260630.xsd#ba_AllowanceForCreditLossExpenseReversal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AllowanceForCreditLossExpenseReversal_019ea99f-cc26-7244-bbaf-b4aca7345f93" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLossesExpensed_019ea99f-cc26-7dcc-a0c2-68c6bc596587" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForLoanLossesExpensed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_ProvisionForLoanLossesExpensed_019ea99f-cc26-7dcc-a0c2-68c6bc596587" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs_019ea99f-cc26-7a6a-ae96-5f020cccc73f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs_019ea99f-cc26-7a6a-ae96-5f020cccc73f" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforCreditLossWriteoff_019ea99f-cc26-7114-90a8-211debbd2d23" xlink:href="ba-20260630.xsd#ba_AllowanceforCreditLossWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AllowanceforCreditLossWriteoff_019ea99f-cc26-7114-90a8-211debbd2d23" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableRecoveries_019ea99f-cc26-75b1-b983-9e5795775feb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableRecoveries"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableRecoveries_019ea99f-cc26-75b1-b983-9e5795775feb" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceForCreditLossRecoveries_019ea99f-cc26-7e40-bbac-b37646dabedd" xlink:href="ba-20260630.xsd#ba_AllowanceForCreditLossRecoveries"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AllowanceForCreditLossRecoveries_019ea99f-cc26-7e40-bbac-b37646dabedd" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AccountsReceivableAllowanceForCreditLossOther_019f1ec1-2a8e-765e-a88e-85825f83e447" xlink:href="ba-20260630.xsd#ba_AccountsReceivableAllowanceForCreditLossOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AccountsReceivableAllowanceForCreditLossOther_019f1ec1-2a8e-765e-a88e-85825f83e447" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_019ea99f-cc26-72e6-8fcf-75d7620b0394" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss_019ea99f-cc26-7ef4-b7b6-3f8cb98ba504" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforCreditLoss_019ea99f-cc26-7800-99cb-419eed18b82d" xlink:href="ba-20260630.xsd#ba_AllowanceforCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019ea99f-cc26-76ea-8415-d62bf7a8130a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/AllowancesforLossesonFinancialAssetsScheduleofFinancialAssetsAllowanceforCreditLossDetails_2" xlink:type="simple" xlink:href="ba-20260630.xsd#AllowancesforLossesonFinancialAssetsScheduleofFinancialAssetsAllowanceforCreditLossDetails_2"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/AllowancesforLossesonFinancialAssetsScheduleofFinancialAssetsAllowanceforCreditLossDetails_2" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforLossesonFinancialAssetsLineItems_019ea99f-cc26-7b4c-aad8-b4dfe45286a5" xlink:href="ba-20260630.xsd#ba_AllowanceforLossesonFinancialAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforLossesonFinancialAssetsTable_019ea99f-cc26-7cc6-844a-4c0b9a06000d" xlink:href="ba-20260630.xsd#ba_AllowanceforLossesonFinancialAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ba_AllowanceforLossesonFinancialAssetsLineItems_019ea99f-cc26-7b4c-aad8-b4dfe45286a5" xlink:to="loc_ba_AllowanceforLossesonFinancialAssetsTable_019ea99f-cc26-7cc6-844a-4c0b9a06000d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfFinancialPositionLocationBalanceAxis_019ea99f-cc26-7660-9343-308a1c554179" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfFinancialPositionLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ba_AllowanceforLossesonFinancialAssetsTable_019ea99f-cc26-7cc6-844a-4c0b9a06000d" xlink:to="loc_us-gaap_StatementOfFinancialPositionLocationBalanceAxis_019ea99f-cc26-7660-9343-308a1c554179" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_AllowanceforLossesonFinancialAssetsLineItems_019ea99f-cc26-7b4c-aad8-b4dfe45286a5" xlink:to="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_019ea99f-cc26-7a3e-b5b5-4e713d7b5070" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_019ea99f-cc26-7a3e-b5b5-4e713d7b5070" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss_019ea99f-cc26-7d74-bd6e-d18f206707f7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss_019ea99f-cc26-7d74-bd6e-d18f206707f7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforCreditLoss_019ea99f-cc26-72ce-9a58-651a1b2377c1" xlink:href="ba-20260630.xsd#ba_AllowanceforCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AllowanceforCreditLoss_019ea99f-cc26-72ce-9a58-651a1b2377c1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019ea99f-cc26-7012-9f37-450baa24f43d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019ea99f-cc26-7012-9f37-450baa24f43d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForDoubtfulAccounts_019ea99f-cc26-79ff-980c-514d4516a908" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForDoubtfulAccounts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_ProvisionForDoubtfulAccounts_019ea99f-cc26-79ff-980c-514d4516a908" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetCreditLossExpense_019ea99f-cc26-780f-bce4-94f63e7fae17" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerAssetCreditLossExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_ContractWithCustomerAssetCreditLossExpense_019ea99f-cc26-780f-bce4-94f63e7fae17" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceForCreditLossExpenseReversal_019ea99f-cc26-7244-bbaf-b4aca7345f93" xlink:href="ba-20260630.xsd#ba_AllowanceForCreditLossExpenseReversal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AllowanceForCreditLossExpenseReversal_019ea99f-cc26-7244-bbaf-b4aca7345f93" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLossesExpensed_019ea99f-cc26-7dcc-a0c2-68c6bc596587" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForLoanLossesExpensed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_ProvisionForLoanLossesExpensed_019ea99f-cc26-7dcc-a0c2-68c6bc596587" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs_019ea99f-cc26-7a6a-ae96-5f020cccc73f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs_019ea99f-cc26-7a6a-ae96-5f020cccc73f" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforCreditLossWriteoff_019ea99f-cc26-7114-90a8-211debbd2d23" xlink:href="ba-20260630.xsd#ba_AllowanceforCreditLossWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AllowanceforCreditLossWriteoff_019ea99f-cc26-7114-90a8-211debbd2d23" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableRecoveries_019ea99f-cc26-75b1-b983-9e5795775feb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableRecoveries"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableRecoveries_019ea99f-cc26-75b1-b983-9e5795775feb" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceForCreditLossRecoveries_019ea99f-cc26-7e40-bbac-b37646dabedd" xlink:href="ba-20260630.xsd#ba_AllowanceForCreditLossRecoveries"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AllowanceForCreditLossRecoveries_019ea99f-cc26-7e40-bbac-b37646dabedd" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AccountsReceivableAllowanceForCreditLossOther_019f1ec1-2a8e-765e-a88e-85825f83e447" xlink:href="ba-20260630.xsd#ba_AccountsReceivableAllowanceForCreditLossOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AccountsReceivableAllowanceForCreditLossOther_019f1ec1-2a8e-765e-a88e-85825f83e447" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_019ea99f-cc26-72e6-8fcf-75d7620b0394" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss_019ea99f-cc26-7ef4-b7b6-3f8cb98ba504" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforCreditLoss_019ea99f-cc26-7800-99cb-419eed18b82d" xlink:href="ba-20260630.xsd#ba_AllowanceforCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019ea99f-cc26-76ea-8415-d62bf7a8130a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/AllowancesforLossesonFinancialAssetsScheduleofFinancialAssetsAllowanceforCreditLossDetails_3" xlink:type="simple" xlink:href="ba-20260630.xsd#AllowancesforLossesonFinancialAssetsScheduleofFinancialAssetsAllowanceforCreditLossDetails_3"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/AllowancesforLossesonFinancialAssetsScheduleofFinancialAssetsAllowanceforCreditLossDetails_3" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforLossesonFinancialAssetsLineItems_019ea99f-cc26-7b4c-aad8-b4dfe45286a5" xlink:href="ba-20260630.xsd#ba_AllowanceforLossesonFinancialAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforLossesonFinancialAssetsTable_019ea99f-cc26-7cc6-844a-4c0b9a06000d" xlink:href="ba-20260630.xsd#ba_AllowanceforLossesonFinancialAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ba_AllowanceforLossesonFinancialAssetsLineItems_019ea99f-cc26-7b4c-aad8-b4dfe45286a5" xlink:to="loc_ba_AllowanceforLossesonFinancialAssetsTable_019ea99f-cc26-7cc6-844a-4c0b9a06000d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SfpLocationActivityAccrualAxis_019ea99f-cc26-7e53-8290-a8c6858e2944" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SfpLocationActivityAccrualAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ba_AllowanceforLossesonFinancialAssetsTable_019ea99f-cc26-7cc6-844a-4c0b9a06000d" xlink:to="loc_us-gaap_SfpLocationActivityAccrualAxis_019ea99f-cc26-7e53-8290-a8c6858e2944" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_AllowanceforLossesonFinancialAssetsLineItems_019ea99f-cc26-7b4c-aad8-b4dfe45286a5" xlink:to="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_019ea99f-cc26-7a3e-b5b5-4e713d7b5070" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_019ea99f-cc26-7a3e-b5b5-4e713d7b5070" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss_019ea99f-cc26-7d74-bd6e-d18f206707f7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss_019ea99f-cc26-7d74-bd6e-d18f206707f7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforCreditLoss_019ea99f-cc26-72ce-9a58-651a1b2377c1" xlink:href="ba-20260630.xsd#ba_AllowanceforCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AllowanceforCreditLoss_019ea99f-cc26-72ce-9a58-651a1b2377c1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019ea99f-cc26-7012-9f37-450baa24f43d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019ea99f-cc26-7012-9f37-450baa24f43d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForDoubtfulAccounts_019ea99f-cc26-79ff-980c-514d4516a908" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForDoubtfulAccounts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_ProvisionForDoubtfulAccounts_019ea99f-cc26-79ff-980c-514d4516a908" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetCreditLossExpense_019ea99f-cc26-780f-bce4-94f63e7fae17" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerAssetCreditLossExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_ContractWithCustomerAssetCreditLossExpense_019ea99f-cc26-780f-bce4-94f63e7fae17" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceForCreditLossExpenseReversal_019ea99f-cc26-7244-bbaf-b4aca7345f93" xlink:href="ba-20260630.xsd#ba_AllowanceForCreditLossExpenseReversal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AllowanceForCreditLossExpenseReversal_019ea99f-cc26-7244-bbaf-b4aca7345f93" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLossesExpensed_019ea99f-cc26-7dcc-a0c2-68c6bc596587" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForLoanLossesExpensed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_ProvisionForLoanLossesExpensed_019ea99f-cc26-7dcc-a0c2-68c6bc596587" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs_019ea99f-cc26-7a6a-ae96-5f020cccc73f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs_019ea99f-cc26-7a6a-ae96-5f020cccc73f" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforCreditLossWriteoff_019ea99f-cc26-7114-90a8-211debbd2d23" xlink:href="ba-20260630.xsd#ba_AllowanceforCreditLossWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AllowanceforCreditLossWriteoff_019ea99f-cc26-7114-90a8-211debbd2d23" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableRecoveries_019ea99f-cc26-75b1-b983-9e5795775feb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableRecoveries"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableRecoveries_019ea99f-cc26-75b1-b983-9e5795775feb" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceForCreditLossRecoveries_019ea99f-cc26-7e40-bbac-b37646dabedd" xlink:href="ba-20260630.xsd#ba_AllowanceForCreditLossRecoveries"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AllowanceForCreditLossRecoveries_019ea99f-cc26-7e40-bbac-b37646dabedd" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AccountsReceivableAllowanceForCreditLossOther_019f1ec1-2a8e-765e-a88e-85825f83e447" xlink:href="ba-20260630.xsd#ba_AccountsReceivableAllowanceForCreditLossOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerAssetAllowanceForCreditLossRollForward_019ea99f-cc26-78de-a7fd-8ae6984b2fd3" xlink:to="loc_ba_AccountsReceivableAllowanceForCreditLossOther_019f1ec1-2a8e-765e-a88e-85825f83e447" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivable_019ea99f-cc26-72e6-8fcf-75d7620b0394" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss_019ea99f-cc26-7ef4-b7b6-3f8cb98ba504" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractWithCustomerAssetAccumulatedAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AllowanceforCreditLoss_019ea99f-cc26-7800-99cb-419eed18b82d" xlink:href="ba-20260630.xsd#ba_AllowanceforCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019ea99f-cc26-76ea-8415-d62bf7a8130a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/InventoriesNarrativeDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#InventoriesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/InventoriesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryLineItems_019ea99f-cc26-7f83-8a4f-7f24ee2f7bd8" 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_019ea99f-cc26-700f-8f8f-578586326678" 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_019ea99f-cc26-7f83-8a4f-7f24ee2f7bd8" xlink:to="loc_us-gaap_InventoryCurrentTable_019ea99f-cc26-700f-8f8f-578586326678" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AircraftTypeAxis_019ea99f-cc26-7ca8-b731-1765392afe2b" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_AircraftTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InventoryCurrentTable_019ea99f-cc26-700f-8f8f-578586326678" xlink:to="loc_srt_AircraftTypeAxis_019ea99f-cc26-7ca8-b731-1765392afe2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AircraftTypeMember_019ea99f-cc26-7ca8-b731-1765392afe2b_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_AircraftTypeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_AircraftTypeAxis_019ea99f-cc26-7ca8-b731-1765392afe2b" xlink:to="loc_srt_AircraftTypeMember_019ea99f-cc26-7ca8-b731-1765392afe2b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AircraftTypeMember_019ea99f-cc26-772b-9d21-74514791523e" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_AircraftTypeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_AircraftTypeAxis_019ea99f-cc26-7ca8-b731-1765392afe2b" xlink:to="loc_srt_AircraftTypeMember_019ea99f-cc26-772b-9d21-74514791523e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AirplaneProgram737Member_019ea99f-cc26-7ddc-a5ea-63c3b8b70582" xlink:href="ba-20260630.xsd#ba_AirplaneProgram737Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_AircraftTypeMember_019ea99f-cc26-772b-9d21-74514791523e" xlink:to="loc_ba_AirplaneProgram737Member_019ea99f-cc26-7ddc-a5ea-63c3b8b70582" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AirplaneProgram777xMember_019ea99f-cc26-784f-80e6-9ed39e2e3643" xlink:href="ba-20260630.xsd#ba_AirplaneProgram777xMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_AircraftTypeMember_019ea99f-cc26-772b-9d21-74514791523e" xlink:to="loc_ba_AirplaneProgram777xMember_019ea99f-cc26-784f-80e6-9ed39e2e3643" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AirplaneProgram787Member_019ea99f-cc26-7a0f-865c-9702db2fe491" xlink:href="ba-20260630.xsd#ba_AirplaneProgram787Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_AircraftTypeMember_019ea99f-cc26-772b-9d21-74514791523e" xlink:to="loc_ba_AirplaneProgram787Member_019ea99f-cc26-7a0f-865c-9702db2fe491" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryAxis_019ea99f-cc26-7d26-a66a-41b115ce8dd1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesInventoryAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InventoryCurrentTable_019ea99f-cc26-700f-8f8f-578586326678" xlink:to="loc_us-gaap_PublicUtilitiesInventoryAxis_019ea99f-cc26-7d26-a66a-41b115ce8dd1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_019ea99f-cc26-7d26-a66a-41b115ce8dd1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesInventoryTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PublicUtilitiesInventoryAxis_019ea99f-cc26-7d26-a66a-41b115ce8dd1" xlink:to="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_019ea99f-cc26-7d26-a66a-41b115ce8dd1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_019ea99f-cc26-7544-9f3c-7de8df38ebff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PublicUtilitiesInventoryTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PublicUtilitiesInventoryAxis_019ea99f-cc26-7d26-a66a-41b115ce8dd1" xlink:to="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_019ea99f-cc26-7544-9f3c-7de8df38ebff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_EarlyIssueSalesConsiderationMember_019ea99f-cc26-71a0-9272-196b113e3bc4" xlink:href="ba-20260630.xsd#ba_EarlyIssueSalesConsiderationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PublicUtilitiesInventoryTypeDomain_019ea99f-cc26-7544-9f3c-7de8df38ebff" xlink:to="loc_ba_EarlyIssueSalesConsiderationMember_019ea99f-cc26-71a0-9272-196b113e3bc4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AmountOfDeferredCostsRelatedToCommercialAircraftPrograms_019ea99f-cc26-758a-ba5b-68736ce82bfb" xlink:href="ba-20260630.xsd#ba_AmountOfDeferredCostsRelatedToCommercialAircraftPrograms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_019ea99f-cc26-7f83-8a4f-7f24ee2f7bd8" xlink:to="loc_ba_AmountOfDeferredCostsRelatedToCommercialAircraftPrograms_019ea99f-cc26-758a-ba5b-68736ce82bfb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_UnamortizedTooling_019ea99f-cc26-792d-95f5-a0bc6faf8efa" xlink:href="ba-20260630.xsd#ba_UnamortizedTooling"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_019ea99f-cc26-7f83-8a4f-7f24ee2f7bd8" xlink:to="loc_ba_UnamortizedTooling_019ea99f-cc26-792d-95f5-a0bc6faf8efa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_RecoveredProductionCostsExcessRecoverableUnderExistingFirmOrders_019ea99f-cc26-734e-9773-7f76fa4e643c" xlink:href="ba-20260630.xsd#ba_RecoveredProductionCostsExcessRecoverableUnderExistingFirmOrders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_019ea99f-cc26-7f83-8a4f-7f24ee2f7bd8" xlink:to="loc_ba_RecoveredProductionCostsExcessRecoverableUnderExistingFirmOrders_019ea99f-cc26-734e-9773-7f76fa4e643c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecoveredProductionCostsExcessUnrecoverableUnderExistingFirmOrders_019ea99f-cc26-78e4-938e-c5362aa239d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrecoveredProductionCostsExcessUnrecoverableUnderExistingFirmOrders"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_019ea99f-cc26-7f83-8a4f-7f24ee2f7bd8" xlink:to="loc_us-gaap_UnrecoveredProductionCostsExcessUnrecoverableUnderExistingFirmOrders_019ea99f-cc26-78e4-938e-c5362aa239d2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryWorkInProcess_019ea99f-cc26-7bae-b3ab-f24fd8e55a2b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryWorkInProcess"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_019ea99f-cc26-7f83-8a4f-7f24ee2f7bd8" xlink:to="loc_us-gaap_InventoryWorkInProcess_019ea99f-cc26-7bae-b3ab-f24fd8e55a2b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdvancesOnInventoryPurchases_019ea99f-cc26-752b-99fe-008e52fa6327" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdvancesOnInventoryPurchases"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_019ea99f-cc26-7f83-8a4f-7f24ee2f7bd8" xlink:to="loc_us-gaap_AdvancesOnInventoryPurchases_019ea99f-cc26-752b-99fe-008e52fa6327" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryAmountUnpricedChangeOrdersForLongTermContractsOrPrograms_019ea99f-cc26-7ac0-b776-aa137a7604b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InventoryAmountUnpricedChangeOrdersForLongTermContractsOrPrograms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InventoryLineItems_019ea99f-cc26-7f83-8a4f-7f24ee2f7bd8" xlink:to="loc_us-gaap_InventoryAmountUnpricedChangeOrdersForLongTermContractsOrPrograms_019ea99f-cc26-7ac0-b776-aa137a7604b8" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/FinancingReceivablesandOperatingLeaseEquipmentNarrativeDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#FinancingReceivablesandOperatingLeaseEquipmentNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/FinancingReceivablesandOperatingLeaseEquipmentNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ba_FinancingReceivablesAndOperatingLeaseEquipmentLineItems_019f82e7-d9ef-737e-baaf-a1ea4983e4b5" xlink:href="ba-20260630.xsd#ba_FinancingReceivablesAndOperatingLeaseEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_FinancingReceivablesAndOperatingLeaseEquipmentTable_019ea99f-cc26-79cb-8dff-567d72018b4f" xlink:href="ba-20260630.xsd#ba_FinancingReceivablesAndOperatingLeaseEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ba_FinancingReceivablesAndOperatingLeaseEquipmentLineItems_019f82e7-d9ef-737e-baaf-a1ea4983e4b5" xlink:to="loc_ba_FinancingReceivablesAndOperatingLeaseEquipmentTable_019ea99f-cc26-79cb-8dff-567d72018b4f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019f82e7-d9ef-7c92-9a2b-7de21047878e" 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_ba_FinancingReceivablesAndOperatingLeaseEquipmentTable_019ea99f-cc26-79cb-8dff-567d72018b4f" xlink:to="loc_srt_RangeAxis_019f82e7-d9ef-7c92-9a2b-7de21047878e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f82e7-d9ef-7c92-9a2b-7de21047878e_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_019f82e7-d9ef-7c92-9a2b-7de21047878e" xlink:to="loc_srt_RangeMember_019f82e7-d9ef-7c92-9a2b-7de21047878e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f82e7-d9ef-7d8c-94c0-9b6ceaebcca4" 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_019f82e7-d9ef-7c92-9a2b-7de21047878e" xlink:to="loc_srt_RangeMember_019f82e7-d9ef-7d8c-94c0-9b6ceaebcca4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019f82e7-d9ef-7528-a4ac-5b65e201791a" 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_019f82e7-d9ef-7d8c-94c0-9b6ceaebcca4" xlink:to="loc_srt_MinimumMember_019f82e7-d9ef-7528-a4ac-5b65e201791a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019f82e7-d9ef-76f0-99d1-a75237308fbe" 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_019f82e7-d9ef-7d8c-94c0-9b6ceaebcca4" xlink:to="loc_srt_MaximumMember_019f82e7-d9ef-76f0-99d1-a75237308fbe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeFinanceLeaseTermOfContract1_019f82e7-d9ef-7189-81aa-fe651cd5e148" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeFinanceLeaseTermOfContract1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_FinancingReceivablesAndOperatingLeaseEquipmentLineItems_019f82e7-d9ef-737e-baaf-a1ea4983e4b5" xlink:to="loc_us-gaap_LesseeFinanceLeaseTermOfContract1_019f82e7-d9ef-7189-81aa-fe651cd5e148" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableGross_019f82e7-d9ef-792b-9732-426301cf712a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesReceivableGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_FinancingReceivablesAndOperatingLeaseEquipmentLineItems_019f82e7-d9ef-737e-baaf-a1ea4983e4b5" xlink:to="loc_us-gaap_NotesReceivableGross_019f82e7-d9ef-792b-9732-426301cf712a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNet_019f82e7-d9ef-7da1-9d54-706dc4285be7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_FinancingReceivablesAndOperatingLeaseEquipmentLineItems_019f82e7-d9ef-737e-baaf-a1ea4983e4b5" xlink:to="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNet_019f82e7-d9ef-7da1-9d54-706dc4285be7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAccumulatedDepreciation_019f82e7-d9ef-71fb-abcf-cd0db6c90e4e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAccumulatedDepreciation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_FinancingReceivablesAndOperatingLeaseEquipmentLineItems_019f82e7-d9ef-737e-baaf-a1ea4983e4b5" xlink:to="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAccumulatedDepreciation_019f82e7-d9ef-71fb-abcf-cd0db6c90e4e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLeaseIncome_019f82e7-f131-7174-bc13-36c830121d5c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLeaseIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_FinancingReceivablesAndOperatingLeaseEquipmentLineItems_019f82e7-d9ef-737e-baaf-a1ea4983e4b5" xlink:to="loc_us-gaap_OperatingLeaseLeaseIncome_019f82e7-f131-7174-bc13-36c830121d5c" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/FinancingReceivablesandOperatingLeaseEquipmentScheduleofCustomerFinancingCarryingValuesRelatedtoMajorAircraftConcentrationsDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#FinancingReceivablesandOperatingLeaseEquipmentScheduleofCustomerFinancingCarryingValuesRelatedtoMajorAircraftConcentrationsDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/FinancingReceivablesandOperatingLeaseEquipmentScheduleofCustomerFinancingCarryingValuesRelatedtoMajorAircraftConcentrationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ba_FinancingReceivablesAndOperatingLeaseEquipmentLineItems_019ea99f-cc26-7ddd-8beb-43982ea5d8d2" xlink:href="ba-20260630.xsd#ba_FinancingReceivablesAndOperatingLeaseEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_FinancingReceivablesAndOperatingLeaseEquipmentTable_019ea99f-cc26-7e1a-9c9d-7b7ccb9c6b58" xlink:href="ba-20260630.xsd#ba_FinancingReceivablesAndOperatingLeaseEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_ba_FinancingReceivablesAndOperatingLeaseEquipmentLineItems_019ea99f-cc26-7ddd-8beb-43982ea5d8d2" xlink:to="loc_ba_FinancingReceivablesAndOperatingLeaseEquipmentTable_019ea99f-cc26-7e1a-9c9d-7b7ccb9c6b58" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AircraftTypeAxis_019ea99f-cc26-7e72-92bf-ffc8e6d0d76f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_AircraftTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_ba_FinancingReceivablesAndOperatingLeaseEquipmentTable_019ea99f-cc26-7e1a-9c9d-7b7ccb9c6b58" xlink:to="loc_srt_AircraftTypeAxis_019ea99f-cc26-7e72-92bf-ffc8e6d0d76f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AircraftTypeMember_019ea99f-cc26-7e72-92bf-ffc8e6d0d76f_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_AircraftTypeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_AircraftTypeAxis_019ea99f-cc26-7e72-92bf-ffc8e6d0d76f" xlink:to="loc_srt_AircraftTypeMember_019ea99f-cc26-7e72-92bf-ffc8e6d0d76f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AircraftTypeMember_019ea99f-cc26-70ab-85f8-cc3153a1afad" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_AircraftTypeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_AircraftTypeAxis_019ea99f-cc26-7e72-92bf-ffc8e6d0d76f" xlink:to="loc_srt_AircraftTypeMember_019ea99f-cc26-70ab-85f8-cc3153a1afad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_B777Member_019ea99f-cc26-7016-a41f-bd10d7e51a0c" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_B777Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_AircraftTypeMember_019ea99f-cc26-70ab-85f8-cc3153a1afad" xlink:to="loc_srt_B777Member_019ea99f-cc26-7016-a41f-bd10d7e51a0c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_B737Member_019ea99f-cc26-75b9-933b-ceb4f4812a48" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_B737Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_AircraftTypeMember_019ea99f-cc26-70ab-85f8-cc3153a1afad" xlink:to="loc_srt_B737Member_019ea99f-cc26-75b9-933b-ceb4f4812a48" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_GrossCustomerFinancingAssets_019ea99f-cc26-7718-b350-d280deda90ac" xlink:href="ba-20260630.xsd#ba_GrossCustomerFinancingAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_FinancingReceivablesAndOperatingLeaseEquipmentLineItems_019ea99f-cc26-7ddd-8beb-43982ea5d8d2" xlink:to="loc_ba_GrossCustomerFinancingAssets_019ea99f-cc26-7718-b350-d280deda90ac" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/InvestmentsScheduleofInvestmentsDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#InvestmentsScheduleofInvestmentsDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/InvestmentsScheduleofInvestmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems_019ea99f-cc26-77d1-b37a-03eaf41c6152" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryTable_019ea99f-cc26-78ce-9051-9e1c2a2303b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems_019ea99f-cc26-77d1-b37a-03eaf41c6152" xlink:to="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryTable_019ea99f-cc26-78ce-9051-9e1c2a2303b8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_019ea99f-cc26-7987-a63f-f36a4dfea10d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryTable_019ea99f-cc26-78ce-9051-9e1c2a2303b8" xlink:to="loc_us-gaap_InvestmentTypeAxis_019ea99f-cc26-7987-a63f-f36a4dfea10d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019ea99f-cc26-7987-a63f-f36a4dfea10d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_019ea99f-cc26-7987-a63f-f36a4dfea10d" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019ea99f-cc26-7987-a63f-f36a4dfea10d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019ea99f-cc26-7ead-9976-b4d560ed3048" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_019ea99f-cc26-7987-a63f-f36a4dfea10d" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019ea99f-cc26-7ead-9976-b4d560ed3048" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_EquityMethodInvestmentsUnitedLaunchAllianceMember_019ea99f-cc26-7dea-967a-ba17a285aac6" xlink:href="ba-20260630.xsd#ba_EquityMethodInvestmentsUnitedLaunchAllianceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019ea99f-cc26-7ead-9976-b4d560ed3048" xlink:to="loc_ba_EquityMethodInvestmentsUnitedLaunchAllianceMember_019ea99f-cc26-7dea-967a-ba17a285aac6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_EquityMethodInvestmentsOtherMember_019ea99f-cc26-7ce2-983b-b02b3338a521" xlink:href="ba-20260630.xsd#ba_EquityMethodInvestmentsOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019ea99f-cc26-7ead-9976-b4d560ed3048" xlink:to="loc_ba_EquityMethodInvestmentsOtherMember_019ea99f-cc26-7ce2-983b-b02b3338a521" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherShortTermInvestments_019ea99f-cc26-7265-a90f-0671f3a9de01" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherShortTermInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems_019ea99f-cc26-77d1-b37a-03eaf41c6152" xlink:to="loc_us-gaap_OtherShortTermInvestments_019ea99f-cc26-7265-a90f-0671f3a9de01" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments_019ea99f-cc26-72a8-b72f-d68f6f292c65" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems_019ea99f-cc26-77d1-b37a-03eaf41c6152" xlink:to="loc_us-gaap_EquityMethodInvestments_019ea99f-cc26-72a8-b72f-d68f6f292c65" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalents_019ea99f-cc26-73cc-a97f-d016c732afd4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems_019ea99f-cc26-77d1-b37a-03eaf41c6152" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalents_019ea99f-cc26-73cc-a97f-d016c732afd4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019ea99f-cc26-78ed-91a6-a579b438c373" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems_019ea99f-cc26-77d1-b37a-03eaf41c6152" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019ea99f-cc26-78ed-91a6-a579b438c373" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherInvestments_019ea99f-cc26-73b6-90da-c65e1e4a1aa1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems_019ea99f-cc26-77d1-b37a-03eaf41c6152" xlink:to="loc_us-gaap_OtherInvestments_019ea99f-cc26-73b6-90da-c65e1e4a1aa1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Investments_019ea99f-cc26-75b7-859b-51ba7ba99385" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Investments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems_019ea99f-cc26-77d1-b37a-03eaf41c6152" xlink:to="loc_us-gaap_Investments_019ea99f-cc26-75b7-859b-51ba7ba99385" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentDividendsOrDistributions_019ea99f-cc26-75c1-9d1b-e7608854d40d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestmentDividendsOrDistributions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems_019ea99f-cc26-77d1-b37a-03eaf41c6152" xlink:to="loc_us-gaap_EquityMethodInvestmentDividendsOrDistributions_019ea99f-cc26-75c1-9d1b-e7608854d40d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EscrowDeposit_019ea99f-cc26-73e2-bf9b-fc58e307ff47" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EscrowDeposit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems_019ea99f-cc26-77d1-b37a-03eaf41c6152" xlink:to="loc_us-gaap_EscrowDeposit_019ea99f-cc26-73e2-bf9b-fc58e307ff47" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/InvestmentsNarrativeDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#InvestmentsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/InvestmentsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems_019ea99f-cc26-78ab-85cc-e6fc32b0d59a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryTable_019ea99f-cc26-7185-a41c-60601061645b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems_019ea99f-cc26-78ab-85cc-e6fc32b0d59a" xlink:to="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryTable_019ea99f-cc26-7185-a41c-60601061645b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_019ea99f-cc26-71ce-89ea-7608e4a5378c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryTable_019ea99f-cc26-7185-a41c-60601061645b" xlink:to="loc_us-gaap_InvestmentTypeAxis_019ea99f-cc26-71ce-89ea-7608e4a5378c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019ea99f-cc26-71ce-89ea-7608e4a5378c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_019ea99f-cc26-71ce-89ea-7608e4a5378c" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019ea99f-cc26-71ce-89ea-7608e4a5378c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019ea99f-cc26-70f9-8e31-0764979d1300" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_019ea99f-cc26-71ce-89ea-7608e4a5378c" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019ea99f-cc26-70f9-8e31-0764979d1300" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_TimeDepositsMember_019ea99f-cc26-7507-9a62-b424a3800ecf" xlink:href="ba-20260630.xsd#ba_TimeDepositsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019ea99f-cc26-70f9-8e31-0764979d1300" xlink:to="loc_ba_TimeDepositsMember_019ea99f-cc26-7507-9a62-b424a3800ecf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_UnitedLaunchAllianceULAMember_019ea99f-cc26-782b-b8b0-6e26ee0ba177" xlink:href="ba-20260630.xsd#ba_UnitedLaunchAllianceULAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019ea99f-cc26-70f9-8e31-0764979d1300" xlink:to="loc_ba_UnitedLaunchAllianceULAMember_019ea99f-cc26-782b-b8b0-6e26ee0ba177" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_019ea99f-cc26-71e7-8f73-ad0bf2973fe7" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryTable_019ea99f-cc26-7185-a41c-60601061645b" xlink:to="loc_srt_CounterpartyNameAxis_019ea99f-cc26-71e7-8f73-ad0bf2973fe7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019ea99f-cc26-71e7-8f73-ad0bf2973fe7_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_019ea99f-cc26-71e7-8f73-ad0bf2973fe7" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019ea99f-cc26-71e7-8f73-ad0bf2973fe7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019ea99f-cc26-797b-8862-967a5f3efaa3" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_019ea99f-cc26-71e7-8f73-ad0bf2973fe7" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019ea99f-cc26-797b-8862-967a5f3efaa3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BoeingCompanyMember_019ea99f-cc26-78f6-aa1e-306dd8fbd4a2" xlink:href="ba-20260630.xsd#ba_BoeingCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019ea99f-cc26-797b-8862-967a5f3efaa3" xlink:to="loc_ba_BoeingCompanyMember_019ea99f-cc26-78f6-aa1e-306dd8fbd4a2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_LockheedMartinCorporationLockheedMember_019ea99f-cc26-7dfc-90f5-96d19380e5e3" xlink:href="ba-20260630.xsd#ba_LockheedMartinCorporationLockheedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019ea99f-cc26-797b-8862-967a5f3efaa3" xlink:to="loc_ba_LockheedMartinCorporationLockheedMember_019ea99f-cc26-7dfc-90f5-96d19380e5e3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsByNatureAxis_019f8314-f683-70a5-8d3b-f349f767895d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsByNatureAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryTable_019ea99f-cc26-7185-a41c-60601061645b" xlink:to="loc_us-gaap_GuaranteeObligationsByNatureAxis_019f8314-f683-70a5-8d3b-f349f767895d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_019f8314-f683-70a5-8d3b-f349f767895d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_019f8314-f683-70a5-8d3b-f349f767895d" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_019f8314-f683-70a5-8d3b-f349f767895d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_019f8314-f683-7de6-97c3-6e23670fb446" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_019f8314-f683-70a5-8d3b-f349f767895d" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_019f8314-f683-7de6-97c3-6e23670fb446" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialGuaranteeMember_019f8314-f683-7200-9131-644e1ac983d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialGuaranteeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsNatureDomain_019f8314-f683-7de6-97c3-6e23670fb446" xlink:to="loc_us-gaap_FinancialGuaranteeMember_019f8314-f683-7200-9131-644e1ac983d7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireInvestments_019ea99f-cc26-7297-97cf-8cc2be60cb19" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquireInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems_019ea99f-cc26-78ab-85cc-e6fc32b0d59a" xlink:to="loc_us-gaap_PaymentsToAcquireInvestments_019ea99f-cc26-7297-97cf-8cc2be60cb19" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments_019ea99f-cc26-7fd2-8ac6-f5b66b2d7fb4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems_019ea99f-cc26-78ab-85cc-e6fc32b0d59a" xlink:to="loc_us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments_019ea99f-cc26-7fd2-8ac6-f5b66b2d7fb4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_InvestmentMembershipInterestOwnershipPercentage_019ea99f-cc26-7234-a747-0d9120e5dc7e" xlink:href="ba-20260630.xsd#ba_InvestmentMembershipInterestOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems_019ea99f-cc26-78ab-85cc-e6fc32b0d59a" xlink:to="loc_ba_InvestmentMembershipInterestOwnershipPercentage_019ea99f-cc26-7234-a747-0d9120e5dc7e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_019f8314-f683-7042-a67e-1058d8940f08" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsCurrentCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems_019ea99f-cc26-78ab-85cc-e6fc32b0d59a" xlink:to="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_019f8314-f683-7042-a67e-1058d8940f08" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/LiabilitiesCommitmentsandContingenciesScheduleof737MaxCustomerConcessionsandOtherConsiderationsLiabilityDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#LiabilitiesCommitmentsandContingenciesScheduleof737MaxCustomerConcessionsandOtherConsiderationsLiabilityDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/LiabilitiesCommitmentsandContingenciesScheduleof737MaxCustomerConcessionsandOtherConsiderationsLiabilityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_019ea99f-cc26-7e58-82aa-0a4c5f2bcd6c" 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_019ea99f-cc26-7909-9bce-ce3b3b0b3b11" 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_019ea99f-cc26-7e58-82aa-0a4c5f2bcd6c" xlink:to="loc_us-gaap_LossContingenciesTable_019ea99f-cc26-7909-9bce-ce3b3b0b3b11" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommercialAircraftProgramsAxis_019ea99f-cc26-774b-a47c-b33428fc871a" xlink:href="ba-20260630.xsd#ba_CommercialAircraftProgramsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019ea99f-cc26-7909-9bce-ce3b3b0b3b11" xlink:to="loc_ba_CommercialAircraftProgramsAxis_019ea99f-cc26-774b-a47c-b33428fc871a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommercialAircraftProgramsDomain_019ea99f-cc26-774b-a47c-b33428fc871a_default" xlink:href="ba-20260630.xsd#ba_CommercialAircraftProgramsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_ba_CommercialAircraftProgramsAxis_019ea99f-cc26-774b-a47c-b33428fc871a" xlink:to="loc_ba_CommercialAircraftProgramsDomain_019ea99f-cc26-774b-a47c-b33428fc871a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommercialAircraftProgramsDomain_019ea99f-cc26-775e-bfdb-29b265256ca4" xlink:href="ba-20260630.xsd#ba_CommercialAircraftProgramsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_ba_CommercialAircraftProgramsAxis_019ea99f-cc26-774b-a47c-b33428fc871a" xlink:to="loc_ba_CommercialAircraftProgramsDomain_019ea99f-cc26-775e-bfdb-29b265256ca4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_B737Member_019ea99f-cc26-7eed-b55d-dcec93119b6f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_B737Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_CommercialAircraftProgramsDomain_019ea99f-cc26-775e-bfdb-29b265256ca4" xlink:to="loc_srt_B737Member_019ea99f-cc26-7eed-b55d-dcec93119b6f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CustomerConcessionAndOtherConsiderationLiabilityRollForward_019ea99f-cc26-77e1-a81b-700ec4f7c313" xlink:href="ba-20260630.xsd#ba_CustomerConcessionAndOtherConsiderationLiabilityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019ea99f-cc26-7e58-82aa-0a4c5f2bcd6c" xlink:to="loc_ba_CustomerConcessionAndOtherConsiderationLiabilityRollForward_019ea99f-cc26-77e1-a81b-700ec4f7c313" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_GroundingCustomerConcessionsAndOtherConsiderationsLiability_019ea99f-cc26-7df0-a776-0bc9700a6b50" xlink:href="ba-20260630.xsd#ba_GroundingCustomerConcessionsAndOtherConsiderationsLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_CustomerConcessionAndOtherConsiderationLiabilityRollForward_019ea99f-cc26-77e1-a81b-700ec4f7c313" xlink:to="loc_ba_GroundingCustomerConcessionsAndOtherConsiderationsLiability_019ea99f-cc26-7df0-a776-0bc9700a6b50" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_PaymentsMadeToCustomers_019ea99f-cc26-729f-a21a-1b9cfa7531a8" xlink:href="ba-20260630.xsd#ba_PaymentsMadeToCustomers"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_CustomerConcessionAndOtherConsiderationLiabilityRollForward_019ea99f-cc26-77e1-a81b-700ec4f7c313" xlink:to="loc_ba_PaymentsMadeToCustomers_019ea99f-cc26-729f-a21a-1b9cfa7531a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_ConcessionsAndOtherInKindConsiderationsToCustomers_019ea99f-cc26-76ff-b1f9-57404bda761e" xlink:href="ba-20260630.xsd#ba_ConcessionsAndOtherInKindConsiderationsToCustomers"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_CustomerConcessionAndOtherConsiderationLiabilityRollForward_019ea99f-cc26-77e1-a81b-700ec4f7c313" xlink:to="loc_ba_ConcessionsAndOtherInKindConsiderationsToCustomers_019ea99f-cc26-76ff-b1f9-57404bda761e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AccrualForCustomerConcessionsAndOtherConsiderationsLiability_019ea99f-cc26-7212-9332-0d64f829ee2f" xlink:href="ba-20260630.xsd#ba_AccrualForCustomerConcessionsAndOtherConsiderationsLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_CustomerConcessionAndOtherConsiderationLiabilityRollForward_019ea99f-cc26-77e1-a81b-700ec4f7c313" xlink:to="loc_ba_AccrualForCustomerConcessionsAndOtherConsiderationsLiability_019ea99f-cc26-7212-9332-0d64f829ee2f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_GroundingCustomerConcessionsAndOtherConsiderationsLiability_019ea99f-cc26-7d1c-b82a-4ad5e12ad709" xlink:href="ba-20260630.xsd#ba_GroundingCustomerConcessionsAndOtherConsiderationsLiability"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/LiabilitiesCommitmentsandContingenciesNarrativeDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#LiabilitiesCommitmentsandContingenciesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/LiabilitiesCommitmentsandContingenciesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_019f8321-8179-753e-bd36-568dda0a5b14" 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_019ea99f-cc26-782b-9c67-ecaa439317e7" 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_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_us-gaap_LossContingenciesTable_019ea99f-cc26-782b-9c67-ecaa439317e7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommitmentTypeAxis_019f8321-a312-765b-b383-74411b1a1a90" xlink:href="ba-20260630.xsd#ba_CommitmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019ea99f-cc26-782b-9c67-ecaa439317e7" xlink:to="loc_ba_CommitmentTypeAxis_019f8321-a312-765b-b383-74411b1a1a90" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommitmentTypeDomain_019f8321-a312-765b-b383-74411b1a1a90_default" xlink:href="ba-20260630.xsd#ba_CommitmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_ba_CommitmentTypeAxis_019f8321-a312-765b-b383-74411b1a1a90" xlink:to="loc_ba_CommitmentTypeDomain_019f8321-a312-765b-b383-74411b1a1a90_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommitmentTypeDomain_019f8321-a312-70c9-936e-226cac305b1c" xlink:href="ba-20260630.xsd#ba_CommitmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_ba_CommitmentTypeAxis_019f8321-a312-765b-b383-74411b1a1a90" xlink:to="loc_ba_CommitmentTypeDomain_019f8321-a312-70c9-936e-226cac305b1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommercialAircraftCommitmentsMember_019f8321-a312-7ab3-b87a-57a91205af34" xlink:href="ba-20260630.xsd#ba_CommercialAircraftCommitmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_CommitmentTypeDomain_019f8321-a312-70c9-936e-226cac305b1c" xlink:to="loc_ba_CommercialAircraftCommitmentsMember_019f8321-a312-7ab3-b87a-57a91205af34" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_FinancingCommitmentMember_019f8321-a312-7708-b4ba-3a2bf3f3b388" xlink:href="ba-20260630.xsd#ba_FinancingCommitmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_CommitmentTypeDomain_019f8321-a312-70c9-936e-226cac305b1c" xlink:to="loc_ba_FinancingCommitmentMember_019f8321-a312-7708-b4ba-3a2bf3f3b388" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_JointVentureMember_019f8321-bd81-7fe2-99c9-f81ce2acdd07" xlink:href="ba-20260630.xsd#ba_JointVentureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_CommitmentTypeDomain_019f8321-a312-70c9-936e-226cac305b1c" xlink:to="loc_ba_JointVentureMember_019f8321-bd81-7fe2-99c9-f81ce2acdd07" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommercialAircraftCommitmentsAxis_019f8321-a312-7776-9912-d8947d0e5aa0" xlink:href="ba-20260630.xsd#ba_CommercialAircraftCommitmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019ea99f-cc26-782b-9c67-ecaa439317e7" xlink:to="loc_ba_CommercialAircraftCommitmentsAxis_019f8321-a312-7776-9912-d8947d0e5aa0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommercialAircraftCommitmentsDomain_019f8321-a312-7776-9912-d8947d0e5aa0_default" xlink:href="ba-20260630.xsd#ba_CommercialAircraftCommitmentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_ba_CommercialAircraftCommitmentsAxis_019f8321-a312-7776-9912-d8947d0e5aa0" xlink:to="loc_ba_CommercialAircraftCommitmentsDomain_019f8321-a312-7776-9912-d8947d0e5aa0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommercialAircraftCommitmentsDomain_019f8321-a312-7375-8e18-690ba4d428bb" xlink:href="ba-20260630.xsd#ba_CommercialAircraftCommitmentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_ba_CommercialAircraftCommitmentsAxis_019f8321-a312-7776-9912-d8947d0e5aa0" xlink:to="loc_ba_CommercialAircraftCommitmentsDomain_019f8321-a312-7375-8e18-690ba4d428bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_TotalContractualTradeInValueMaximumMember_019f8321-a312-787f-86b7-e9945e409bc4" xlink:href="ba-20260630.xsd#ba_TotalContractualTradeInValueMaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_CommercialAircraftCommitmentsDomain_019f8321-a312-7375-8e18-690ba4d428bb" xlink:to="loc_ba_TotalContractualTradeInValueMaximumMember_019f8321-a312-787f-86b7-e9945e409bc4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_NetAmountsPayableToCustomersRelatedToProbableContractualTradeInCommitmentsMember_019f8321-a312-7467-8ce7-c7140746d282" xlink:href="ba-20260630.xsd#ba_NetAmountsPayableToCustomersRelatedToProbableContractualTradeInCommitmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_CommercialAircraftCommitmentsDomain_019f8321-a312-7375-8e18-690ba4d428bb" xlink:to="loc_ba_NetAmountsPayableToCustomersRelatedToProbableContractualTradeInCommitmentsMember_019f8321-a312-7467-8ce7-c7140746d282" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_ProbableContractualTradeInValueMember_019f8321-a312-7f0a-bb00-45005366542b" xlink:href="ba-20260630.xsd#ba_ProbableContractualTradeInValueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_CommercialAircraftCommitmentsDomain_019f8321-a312-7375-8e18-690ba4d428bb" xlink:to="loc_ba_ProbableContractualTradeInValueMember_019f8321-a312-7f0a-bb00-45005366542b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExternalCreditRatingByGroupingAxis_019f8321-bd81-7648-aaf1-7af92ed1da05" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ExternalCreditRatingByGroupingAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019ea99f-cc26-782b-9c67-ecaa439317e7" xlink:to="loc_us-gaap_ExternalCreditRatingByGroupingAxis_019f8321-bd81-7648-aaf1-7af92ed1da05" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExternalCreditRatingByGroupingDomain_019f8321-bd81-7648-aaf1-7af92ed1da05_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ExternalCreditRatingByGroupingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ExternalCreditRatingByGroupingAxis_019f8321-bd81-7648-aaf1-7af92ed1da05" xlink:to="loc_us-gaap_ExternalCreditRatingByGroupingDomain_019f8321-bd81-7648-aaf1-7af92ed1da05_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExternalCreditRatingByGroupingDomain_019f8321-bd81-7220-9e19-cf81f9fd6abe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ExternalCreditRatingByGroupingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ExternalCreditRatingByGroupingAxis_019f8321-bd81-7648-aaf1-7af92ed1da05" xlink:to="loc_us-gaap_ExternalCreditRatingByGroupingDomain_019f8321-bd81-7220-9e19-cf81f9fd6abe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExternalCreditRatingNonInvestmentGradeMember_019f8321-bd81-7535-add0-fe1e81934d85" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ExternalCreditRatingNonInvestmentGradeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ExternalCreditRatingByGroupingDomain_019f8321-bd81-7220-9e19-cf81f9fd6abe" xlink:to="loc_us-gaap_ExternalCreditRatingNonInvestmentGradeMember_019f8321-bd81-7535-add0-fe1e81934d85" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019f8321-dda2-7c82-90d6-bae5de997d21" 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_LossContingenciesTable_019ea99f-cc26-782b-9c67-ecaa439317e7" xlink:to="loc_srt_RangeAxis_019f8321-dda2-7c82-90d6-bae5de997d21" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f8321-dda2-7c82-90d6-bae5de997d21_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_019f8321-dda2-7c82-90d6-bae5de997d21" xlink:to="loc_srt_RangeMember_019f8321-dda2-7c82-90d6-bae5de997d21_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f8321-dda2-7649-bc38-79ef6b11b781" 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_019f8321-dda2-7c82-90d6-bae5de997d21" xlink:to="loc_srt_RangeMember_019f8321-dda2-7649-bc38-79ef6b11b781" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019f8321-dda2-70d8-9639-d672e59ad1a1" 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_019f8321-dda2-7649-bc38-79ef6b11b781" xlink:to="loc_srt_MinimumMember_019f8321-dda2-70d8-9639-d672e59ad1a1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019f8321-dda2-70df-bf81-edd84f243382" 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_019f8321-dda2-7649-bc38-79ef6b11b781" xlink:to="loc_srt_MaximumMember_019f8321-dda2-70df-bf81-edd84f243382" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplierFinanceProgramAxis_019f8321-dda2-77a4-8bb8-1f9141050195" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SupplierFinanceProgramAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019ea99f-cc26-782b-9c67-ecaa439317e7" xlink:to="loc_us-gaap_SupplierFinanceProgramAxis_019f8321-dda2-77a4-8bb8-1f9141050195" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplierFinanceProgramDomain_019f8321-dda2-77a4-8bb8-1f9141050195_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SupplierFinanceProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SupplierFinanceProgramAxis_019f8321-dda2-77a4-8bb8-1f9141050195" xlink:to="loc_us-gaap_SupplierFinanceProgramDomain_019f8321-dda2-77a4-8bb8-1f9141050195_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplierFinanceProgramDomain_019f8321-dda2-76a5-af85-1445848bf88e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SupplierFinanceProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SupplierFinanceProgramAxis_019f8321-dda2-77a4-8bb8-1f9141050195" xlink:to="loc_us-gaap_SupplierFinanceProgramDomain_019f8321-dda2-76a5-af85-1445848bf88e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_SupplierFinanceProgramMajorityOfAmountsPayableMember_019f8321-dda2-71b1-af39-9f3a57db6ea0" xlink:href="ba-20260630.xsd#ba_SupplierFinanceProgramMajorityOfAmountsPayableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplierFinanceProgramDomain_019f8321-dda2-76a5-af85-1445848bf88e" xlink:to="loc_ba_SupplierFinanceProgramMajorityOfAmountsPayableMember_019f8321-dda2-71b1-af39-9f3a57db6ea0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_ProgramAxis_019f8322-0ed5-7078-afdb-9c6d94021ed9" xlink:href="ba-20260630.xsd#ba_ProgramAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019ea99f-cc26-782b-9c67-ecaa439317e7" xlink:to="loc_ba_ProgramAxis_019f8322-0ed5-7078-afdb-9c6d94021ed9" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_ProgramDomain_019f8322-0ed5-7078-afdb-9c6d94021ed9_default" xlink:href="ba-20260630.xsd#ba_ProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_ba_ProgramAxis_019f8322-0ed5-7078-afdb-9c6d94021ed9" xlink:to="loc_ba_ProgramDomain_019f8322-0ed5-7078-afdb-9c6d94021ed9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_ProgramDomain_019f8322-0ed5-77b9-a3a9-9f32f900a919" xlink:href="ba-20260630.xsd#ba_ProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_ba_ProgramAxis_019f8322-0ed5-7078-afdb-9c6d94021ed9" xlink:to="loc_ba_ProgramDomain_019f8322-0ed5-77b9-a3a9-9f32f900a919" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_VC25BMember_019f8322-0ed5-7d0d-82d7-ab4c20046168" xlink:href="ba-20260630.xsd#ba_VC25BMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_ProgramDomain_019f8322-0ed5-77b9-a3a9-9f32f900a919" xlink:to="loc_ba_VC25BMember_019f8322-0ed5-7d0d-82d7-ab4c20046168" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_KC46ATankerMember_019f8322-0ed5-7e32-91d2-fc85eb1bd7da" xlink:href="ba-20260630.xsd#ba_KC46ATankerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_ProgramDomain_019f8322-0ed5-77b9-a3a9-9f32f900a919" xlink:to="loc_ba_KC46ATankerMember_019f8322-0ed5-7e32-91d2-fc85eb1bd7da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_MQ25Member_019f8322-3457-75f7-9c76-58b7a0d33d4e" xlink:href="ba-20260630.xsd#ba_MQ25Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_ProgramDomain_019f8322-0ed5-77b9-a3a9-9f32f900a919" xlink:to="loc_ba_MQ25Member_019f8322-3457-75f7-9c76-58b7a0d33d4e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_T7AEMDMember_019f8322-52a8-7eb5-8076-db1a54472e1b" xlink:href="ba-20260630.xsd#ba_T7AEMDMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_ProgramDomain_019f8322-0ed5-77b9-a3a9-9f32f900a919" xlink:to="loc_ba_T7AEMDMember_019f8322-52a8-7eb5-8076-db1a54472e1b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_T7AProductionMember_019f8322-52a8-7616-83a3-f5b83bfa4e04" xlink:href="ba-20260630.xsd#ba_T7AProductionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_ProgramDomain_019f8322-0ed5-77b9-a3a9-9f32f900a919" xlink:to="loc_ba_T7AProductionMember_019f8322-52a8-7616-83a3-f5b83bfa4e04" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommercialCrewMember_019f8322-6951-7b67-a076-c119e63f2a66" xlink:href="ba-20260630.xsd#ba_CommercialCrewMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_ProgramDomain_019f8322-0ed5-77b9-a3a9-9f32f900a919" xlink:to="loc_ba_CommercialCrewMember_019f8322-6951-7b67-a076-c119e63f2a66" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_019f8322-0ed5-7537-b763-65600dcad759" 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_019ea99f-cc26-782b-9c67-ecaa439317e7" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_019f8322-0ed5-7537-b763-65600dcad759" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_019f8322-0ed5-7537-b763-65600dcad759_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_019f8322-0ed5-7537-b763-65600dcad759" xlink:to="loc_us-gaap_LossContingencyNatureDomain_019f8322-0ed5-7537-b763-65600dcad759_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_019f8322-0ed5-73dd-b2aa-408e561ac590" 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_019f8322-0ed5-7537-b763-65600dcad759" xlink:to="loc_us-gaap_LossContingencyNatureDomain_019f8322-0ed5-73dd-b2aa-408e561ac590" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CapitalizedPrecontractCostsMember_019f8322-0ed5-7b2d-bf6c-97d71231e87d" xlink:href="ba-20260630.xsd#ba_CapitalizedPrecontractCostsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_019f8322-0ed5-73dd-b2aa-408e561ac590" xlink:to="loc_ba_CapitalizedPrecontractCostsMember_019f8322-0ed5-7b2d-bf6c-97d71231e87d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_PotentialTerminationLiabilitiesMember_019f8322-0ed5-7cc2-a99d-49582440c6ac" xlink:href="ba-20260630.xsd#ba_PotentialTerminationLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_019f8322-0ed5-73dd-b2aa-408e561ac590" xlink:to="loc_ba_PotentialTerminationLiabilitiesMember_019f8322-0ed5-7cc2-a99d-49582440c6ac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_EnvironmentalLossContingencyOperationAndMaintenancePeriodMaximum_019f8321-8179-7246-9aad-29577d650727" xlink:href="ba-20260630.xsd#ba_EnvironmentalLossContingencyOperationAndMaintenancePeriodMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_ba_EnvironmentalLossContingencyOperationAndMaintenancePeriodMaximum_019f8321-8179-7246-9aad-29577d650727" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyRangeOfPossibleLossPortionNotAccrued_019f8321-8179-7b88-bd0d-9763ce038ebc" 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_LossContingenciesLineItems_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_us-gaap_LossContingencyRangeOfPossibleLossPortionNotAccrued_019f8321-8179-7b88-bd0d-9763ce038ebc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitment_019f8321-a312-74d5-8b35-810ee523b532" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_us-gaap_OtherCommitment_019f8321-a312-74d5-8b35-810ee523b532" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_OtherCommitmentPeriod_019f8321-bd81-72d6-8a86-6a2d4c15809f" xlink:href="ba-20260630.xsd#ba_OtherCommitmentPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_ba_OtherCommitmentPeriod_019f8321-bd81-72d6-8a86-6a2d4c15809f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_019f8321-bd81-79b2-bdf7-847c4fdcba0e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_019f8321-bd81-79b2-bdf7-847c4fdcba0e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplierFinanceProgramPaymentTimingPeriod_019f8321-dda2-7429-8d6b-c76481f16e02" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SupplierFinanceProgramPaymentTimingPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_us-gaap_SupplierFinanceProgramPaymentTimingPeriod_019f8321-dda2-7429-8d6b-c76481f16e02" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplierFinanceProgramObligation_019f8321-dda2-7c64-841e-76dabb01c31f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SupplierFinanceProgramObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_us-gaap_SupplierFinanceProgramObligation_019f8321-dda2-7c64-841e-76dabb01c31f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_ContractValue_019f8322-0ed5-7f18-a33d-94212736ed38" xlink:href="ba-20260630.xsd#ba_ContractValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_ba_ContractValue_019f8322-0ed5-7f18-a33d-94212736ed38" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_NumberOfCommercialAircraft_019f8322-0ed5-7c56-b067-2e3349809f84" xlink:href="ba-20260630.xsd#ba_NumberOfCommercialAircraft"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_ba_NumberOfCommercialAircraft_019f8322-0ed5-7c56-b067-2e3349809f84" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_IncreaseDecreaseInEarningsFromOperationsDueToChangeInAccountingEstimate_019f8322-0ed5-7f49-88c2-ee8d0479561f" xlink:href="ba-20260630.xsd#ba_IncreaseDecreaseInEarningsFromOperationsDueToChangeInAccountingEstimate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_ba_IncreaseDecreaseInEarningsFromOperationsDueToChangeInAccountingEstimate_019f8322-0ed5-7f49-88c2-ee8d0479561f" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_NumberOfGenerationAerialRefuelingTanker_019f8322-0ed5-74cb-be56-cd686486db2f" xlink:href="ba-20260630.xsd#ba_NumberOfGenerationAerialRefuelingTanker"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_ba_NumberOfGenerationAerialRefuelingTanker_019f8322-0ed5-74cb-be56-cd686486db2f" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_NumberOfAnnualProductionLot_019f8322-0ed5-7272-b5a2-53d685f83fbf" xlink:href="ba-20260630.xsd#ba_NumberOfAnnualProductionLot"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_ba_NumberOfAnnualProductionLot_019f8322-0ed5-7272-b5a2-53d685f83fbf" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_NumberOfAircraft_019f8322-0ed5-78cc-945b-206d41b1c83e" xlink:href="ba-20260630.xsd#ba_NumberOfAircraft"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_ba_NumberOfAircraft_019f8322-0ed5-78cc-945b-206d41b1c83e" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_NumberOfLowRateInitialProductionLot_019f8322-0ed5-7408-95f2-07b1caa08bc1" xlink:href="ba-20260630.xsd#ba_NumberOfLowRateInitialProductionLot"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_ba_NumberOfLowRateInitialProductionLot_019f8322-0ed5-7408-95f2-07b1caa08bc1" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyEstimateOfPossibleLoss_019f8322-0ed5-7ec8-838f-dba46fca082e" 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_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_us-gaap_LossContingencyEstimateOfPossibleLoss_019f8322-0ed5-7ec8-838f-dba46fca082e" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_NumberOfSimulator_019f8322-52a8-7599-9426-e562bad47b2f" xlink:href="ba-20260630.xsd#ba_NumberOfSimulator"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_ba_NumberOfSimulator_019f8322-52a8-7599-9426-e562bad47b2f" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_NumberOfTestVehicle_019f8322-52a8-77f8-917f-ce758e8a89f3" xlink:href="ba-20260630.xsd#ba_NumberOfTestVehicle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_ba_NumberOfTestVehicle_019f8322-52a8-77f8-917f-ce758e8a89f3" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_NumberOfProductionLot_019f8322-52a8-706b-97ac-12e2a91d050b" xlink:href="ba-20260630.xsd#ba_NumberOfProductionLot"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019f8321-8179-753e-bd36-568dda0a5b14" xlink:to="loc_ba_NumberOfProductionLot_019f8322-52a8-706b-97ac-12e2a91d050b" xlink:type="arc" order="17"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/LiabilitiesCommitmentsandContingenciesScheduleofContractualObligationFiscalYearMaturityDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#LiabilitiesCommitmentsandContingenciesScheduleofContractualObligationFiscalYearMaturityDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/LiabilitiesCommitmentsandContingenciesScheduleofContractualObligationFiscalYearMaturityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsLineItems_019ea99f-cc26-7fc3-acbe-a0b14c3a85ba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_019ea99f-cc26-773c-a1a7-5717f33474b2" 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_OtherCommitmentsLineItems_019ea99f-cc26-7fc3-acbe-a0b14c3a85ba" xlink:to="loc_us-gaap_LossContingenciesTable_019ea99f-cc26-773c-a1a7-5717f33474b2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommitmentTypeAxis_019ea99f-cc26-766b-84d4-fbad93307fe4" xlink:href="ba-20260630.xsd#ba_CommitmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019ea99f-cc26-773c-a1a7-5717f33474b2" xlink:to="loc_ba_CommitmentTypeAxis_019ea99f-cc26-766b-84d4-fbad93307fe4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommitmentTypeDomain_019ea99f-cc26-766b-84d4-fbad93307fe4_default" xlink:href="ba-20260630.xsd#ba_CommitmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_ba_CommitmentTypeAxis_019ea99f-cc26-766b-84d4-fbad93307fe4" xlink:to="loc_ba_CommitmentTypeDomain_019ea99f-cc26-766b-84d4-fbad93307fe4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommitmentTypeDomain_019ea99f-cc26-7455-84f8-00f7dbb19fbc" xlink:href="ba-20260630.xsd#ba_CommitmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_ba_CommitmentTypeAxis_019ea99f-cc26-766b-84d4-fbad93307fe4" xlink:to="loc_ba_CommitmentTypeDomain_019ea99f-cc26-7455-84f8-00f7dbb19fbc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_FinancingCommitmentMember_019ea99f-cc26-7f82-82c7-fe6bdf6b9eba" xlink:href="ba-20260630.xsd#ba_FinancingCommitmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_CommitmentTypeDomain_019ea99f-cc26-7455-84f8-00f7dbb19fbc" xlink:to="loc_ba_FinancingCommitmentMember_019ea99f-cc26-7f82-82c7-fe6bdf6b9eba" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsFutureMinimumPaymentsRemainderOfFiscalYear_019ea99f-cc26-726d-8e40-fd8e9dde7b35" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentsFutureMinimumPaymentsRemainderOfFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019ea99f-cc26-7fc3-acbe-a0b14c3a85ba" xlink:to="loc_us-gaap_OtherCommitmentsFutureMinimumPaymentsRemainderOfFiscalYear_019ea99f-cc26-726d-8e40-fd8e9dde7b35" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentDueInNextTwelveMonths_019ea99f-cc26-7210-bc61-7e4105beee38" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentDueInNextTwelveMonths"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019ea99f-cc26-7fc3-acbe-a0b14c3a85ba" xlink:to="loc_us-gaap_OtherCommitmentDueInNextTwelveMonths_019ea99f-cc26-7210-bc61-7e4105beee38" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentDueInSecondYear_019ea99f-cc26-7d81-8aff-e8f6ad38eee2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentDueInSecondYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019ea99f-cc26-7fc3-acbe-a0b14c3a85ba" xlink:to="loc_us-gaap_OtherCommitmentDueInSecondYear_019ea99f-cc26-7d81-8aff-e8f6ad38eee2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentDueInThirdYear_019ea99f-cc26-7ce4-b8fc-bc31940ed327" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentDueInThirdYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019ea99f-cc26-7fc3-acbe-a0b14c3a85ba" xlink:to="loc_us-gaap_OtherCommitmentDueInThirdYear_019ea99f-cc26-7ce4-b8fc-bc31940ed327" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentDueInFourthYear_019ea99f-cc26-73bd-8a79-13ea2a7984fa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentDueInFourthYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019ea99f-cc26-7fc3-acbe-a0b14c3a85ba" xlink:to="loc_us-gaap_OtherCommitmentDueInFourthYear_019ea99f-cc26-73bd-8a79-13ea2a7984fa" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_OtherCommitmentToBePaidAfterYearFour_019ea99f-cc26-7661-8717-08e18e2cf0f7" xlink:href="ba-20260630.xsd#ba_OtherCommitmentToBePaidAfterYearFour"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019ea99f-cc26-7fc3-acbe-a0b14c3a85ba" xlink:to="loc_ba_OtherCommitmentToBePaidAfterYearFour_019ea99f-cc26-7661-8717-08e18e2cf0f7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitment_019ea99f-cc26-7156-8ed7-14da1e7e54f0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_019ea99f-cc26-7fc3-acbe-a0b14c3a85ba" xlink:to="loc_us-gaap_OtherCommitment_019ea99f-cc26-7156-8ed7-14da1e7e54f0" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/ArrangementswithOffBalanceSheetRiskScheduleofGuarantorObligationsDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#ArrangementswithOffBalanceSheetRiskScheduleofGuarantorObligationsDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/ArrangementswithOffBalanceSheetRiskScheduleofGuarantorObligationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsLineItems_019ea99f-cc26-7f5c-864a-f2c033477e2d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGuaranteeObligationsTable_019ea99f-cc26-7bec-bbfb-163a58dca7b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfGuaranteeObligationsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GuaranteeObligationsLineItems_019ea99f-cc26-7f5c-864a-f2c033477e2d" xlink:to="loc_us-gaap_ScheduleOfGuaranteeObligationsTable_019ea99f-cc26-7bec-bbfb-163a58dca7b5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsByNatureAxis_019ea99f-cc26-743a-82e9-b76c18e2a824" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsByNatureAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGuaranteeObligationsTable_019ea99f-cc26-7bec-bbfb-163a58dca7b5" xlink:to="loc_us-gaap_GuaranteeObligationsByNatureAxis_019ea99f-cc26-743a-82e9-b76c18e2a824" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_019ea99f-cc26-743a-82e9-b76c18e2a824_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_019ea99f-cc26-743a-82e9-b76c18e2a824" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_019ea99f-cc26-743a-82e9-b76c18e2a824_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_019ea99f-cc26-7ff4-8b82-db49679454cc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_019ea99f-cc26-743a-82e9-b76c18e2a824" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_019ea99f-cc26-7ff4-8b82-db49679454cc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_ContingentRepurchaseCommitmentMember_019ea99f-cc26-7661-a49e-f1c2368d5ee7" xlink:href="ba-20260630.xsd#ba_ContingentRepurchaseCommitmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsNatureDomain_019ea99f-cc26-7ff4-8b82-db49679454cc" xlink:to="loc_ba_ContingentRepurchaseCommitmentMember_019ea99f-cc26-7661-a49e-f1c2368d5ee7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialGuaranteeMember_019ea99f-cc26-7c7e-8437-62f25dcb8401" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialGuaranteeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsNatureDomain_019ea99f-cc26-7ff4-8b82-db49679454cc" xlink:to="loc_us-gaap_FinancialGuaranteeMember_019ea99f-cc26-7c7e-8437-62f25dcb8401" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsMaximumExposure_019ea99f-cc26-7085-bee6-bf932a13f2ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsMaximumExposure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsLineItems_019ea99f-cc26-7f5c-864a-f2c033477e2d" xlink:to="loc_us-gaap_GuaranteeObligationsMaximumExposure_019ea99f-cc26-7085-bee6-bf932a13f2ea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsLiquidationProceeds_019ea99f-cc26-7370-becb-68e0cb9022d1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsLiquidationProceeds"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsLineItems_019ea99f-cc26-7f5c-864a-f2c033477e2d" xlink:to="loc_us-gaap_GuaranteeObligationsLiquidationProceeds_019ea99f-cc26-7370-becb-68e0cb9022d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_019ea99f-cc26-74cc-9171-7d8388b1775c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsCurrentCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsLineItems_019ea99f-cc26-7f5c-864a-f2c033477e2d" xlink:to="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_019ea99f-cc26-74cc-9171-7d8388b1775c" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/ArrangementswithOffBalanceSheetRiskNarrativeDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#ArrangementswithOffBalanceSheetRiskNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/ArrangementswithOffBalanceSheetRiskNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsLineItems_019ea99f-cc26-7ee2-9bd2-2e95205698e9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGuaranteeObligationsTable_019ea99f-cc26-72f8-9f0f-cfa06fe074b7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfGuaranteeObligationsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GuaranteeObligationsLineItems_019ea99f-cc26-7ee2-9bd2-2e95205698e9" xlink:to="loc_us-gaap_ScheduleOfGuaranteeObligationsTable_019ea99f-cc26-72f8-9f0f-cfa06fe074b7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019ea99f-cc26-7d62-84cb-8cb2c38f525d" 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_ScheduleOfGuaranteeObligationsTable_019ea99f-cc26-72f8-9f0f-cfa06fe074b7" xlink:to="loc_srt_RangeAxis_019ea99f-cc26-7d62-84cb-8cb2c38f525d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019ea99f-cc26-7d62-84cb-8cb2c38f525d_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_019ea99f-cc26-7d62-84cb-8cb2c38f525d" xlink:to="loc_srt_RangeMember_019ea99f-cc26-7d62-84cb-8cb2c38f525d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019ea99f-cc26-7dc4-bcf4-f94db4e574d3" 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_019ea99f-cc26-7d62-84cb-8cb2c38f525d" xlink:to="loc_srt_RangeMember_019ea99f-cc26-7dc4-bcf4-f94db4e574d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019ea99f-cc26-75eb-85ff-a2194cb8ca3a" 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_019ea99f-cc26-7dc4-bcf4-f94db4e574d3" xlink:to="loc_srt_MinimumMember_019ea99f-cc26-75eb-85ff-a2194cb8ca3a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019ea99f-cc26-71ae-9485-5464d72cdfce" 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_019ea99f-cc26-7dc4-bcf4-f94db4e574d3" xlink:to="loc_srt_MaximumMember_019ea99f-cc26-71ae-9485-5464d72cdfce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsByNatureAxis_019ea99f-cc26-7647-8f20-e23e76e41481" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsByNatureAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGuaranteeObligationsTable_019ea99f-cc26-72f8-9f0f-cfa06fe074b7" xlink:to="loc_us-gaap_GuaranteeObligationsByNatureAxis_019ea99f-cc26-7647-8f20-e23e76e41481" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_019ea99f-cc26-7647-8f20-e23e76e41481_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_019ea99f-cc26-7647-8f20-e23e76e41481" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_019ea99f-cc26-7647-8f20-e23e76e41481_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_019ea99f-cc26-78b6-b505-90b4630a41b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_019ea99f-cc26-7647-8f20-e23e76e41481" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_019ea99f-cc26-78b6-b505-90b4630a41b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_ContingentRepurchaseCommitmentMember_019ea99f-cc26-78b7-9619-04c059d5c9f5" xlink:href="ba-20260630.xsd#ba_ContingentRepurchaseCommitmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsNatureDomain_019ea99f-cc26-78b6-b505-90b4630a41b5" xlink:to="loc_ba_ContingentRepurchaseCommitmentMember_019ea99f-cc26-78b7-9619-04c059d5c9f5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialGuaranteeMember_019f1eea-cac6-7d0d-9114-e1abca0f2067" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialGuaranteeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsNatureDomain_019ea99f-cc26-78b6-b505-90b4630a41b5" xlink:to="loc_us-gaap_FinancialGuaranteeMember_019f1eea-cac6-7d0d-9114-e1abca0f2067" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_GuarantorObligationsRepurchaseCommitmentPeriodPostDelivery_019ea99f-cc26-7103-b1a2-b9fbf2dec193" xlink:href="ba-20260630.xsd#ba_GuarantorObligationsRepurchaseCommitmentPeriodPostDelivery"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsLineItems_019ea99f-cc26-7ee2-9bd2-2e95205698e9" xlink:to="loc_ba_GuarantorObligationsRepurchaseCommitmentPeriodPostDelivery_019ea99f-cc26-7103-b1a2-b9fbf2dec193" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_019f1eea-cac6-782e-8db7-1316c2e379c6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsCurrentCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsLineItems_019ea99f-cc26-7ee2-9bd2-2e95205698e9" xlink:to="loc_us-gaap_GuaranteeObligationsCurrentCarryingValue_019f1eea-cac6-782e-8db7-1316c2e379c6" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/DebtDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#DebtDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/DebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019ea99f-cc26-7739-ae96-7db04a2ea9da" 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_019ea99f-cc26-7fef-a8ad-317c3d22f3fc" 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_019ea99f-cc26-7739-ae96-7db04a2ea9da" xlink:to="loc_us-gaap_DebtInstrumentTable_019ea99f-cc26-7fef-a8ad-317c3d22f3fc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_019ea99f-cc26-760d-b4f5-3b3af38e175c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_019ea99f-cc26-7fef-a8ad-317c3d22f3fc" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_019ea99f-cc26-760d-b4f5-3b3af38e175c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-760d-b4f5-3b3af38e175c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019ea99f-cc26-760d-b4f5-3b3af38e175c" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-760d-b4f5-3b3af38e175c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-7f2b-80b1-dec700eb0b7a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_019ea99f-cc26-760d-b4f5-3b3af38e175c" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-7f2b-80b1-dec700eb0b7a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_SpiritAeroSystemsHoldingsInc.Member_019ea99f-cc26-78cf-9dbe-5d7d5042dab5" xlink:href="ba-20260630.xsd#ba_SpiritAeroSystemsHoldingsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_019ea99f-cc26-7f2b-80b1-dec700eb0b7a" xlink:to="loc_ba_SpiritAeroSystemsHoldingsInc.Member_019ea99f-cc26-78cf-9dbe-5d7d5042dab5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019ea99f-cc26-7335-905f-c78cb5d93d1d" 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_019ea99f-cc26-7fef-a8ad-317c3d22f3fc" xlink:to="loc_us-gaap_DebtInstrumentAxis_019ea99f-cc26-7335-905f-c78cb5d93d1d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019ea99f-cc26-7335-905f-c78cb5d93d1d_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_019ea99f-cc26-7335-905f-c78cb5d93d1d" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019ea99f-cc26-7335-905f-c78cb5d93d1d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019ea99f-cc26-7588-82db-9675b68bbda5" 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_019ea99f-cc26-7335-905f-c78cb5d93d1d" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019ea99f-cc26-7588-82db-9675b68bbda5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_SeniorNotesDue2026Member_019ea99f-cc26-7883-805e-284287da27ca" xlink:href="ba-20260630.xsd#ba_SeniorNotesDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019ea99f-cc26-7588-82db-9675b68bbda5" xlink:to="loc_ba_SeniorNotesDue2026Member_019ea99f-cc26-7883-805e-284287da27ca" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_SeniorNotesDue2028Member_019ea99f-cc26-7b8f-a347-1a081eab4422" xlink:href="ba-20260630.xsd#ba_SeniorNotesDue2028Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019ea99f-cc26-7588-82db-9675b68bbda5" xlink:to="loc_ba_SeniorNotesDue2028Member_019ea99f-cc26-7b8f-a347-1a081eab4422" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019ea99f-cc26-7555-bbda-69416d087ce0" 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_DebtInstrumentTable_019ea99f-cc26-7fef-a8ad-317c3d22f3fc" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019ea99f-cc26-7555-bbda-69416d087ce0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019ea99f-cc26-7555-bbda-69416d087ce0_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_019ea99f-cc26-7555-bbda-69416d087ce0" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019ea99f-cc26-7555-bbda-69416d087ce0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019ea99f-cc26-7e1f-8fef-ceefca3f87df" 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_019ea99f-cc26-7555-bbda-69416d087ce0" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019ea99f-cc26-7e1f-8fef-ceefca3f87df" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_019ea99f-cc26-77b5-a15f-39bd407edde2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019ea99f-cc26-7e1f-8fef-ceefca3f87df" xlink:to="loc_us-gaap_SeniorNotesMember_019ea99f-cc26-77b5-a15f-39bd407edde2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLongTermDebtOutstanding_019ea99f-cc26-752e-a3fb-f49811a4ef89" xlink:href="ba-20260630.xsd#ba_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLongTermDebtOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019ea99f-cc26-7739-ae96-7db04a2ea9da" xlink:to="loc_ba_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLongTermDebtOutstanding_019ea99f-cc26-752e-a3fb-f49811a4ef89" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019ea99f-cc26-7baf-bffd-f5b81ed6c37c" 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_019ea99f-cc26-7739-ae96-7db04a2ea9da" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_019ea99f-cc26-7baf-bffd-f5b81ed6c37c" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/PostretirementPlansComponentsofNetPeriodicBenefitCostDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#PostretirementPlansComponentsofNetPeriodicBenefitCostDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/PostretirementPlansComponentsofNetPeriodicBenefitCostDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019ea99f-cc26-725f-826f-090140c6ce98" 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_019ea99f-cc26-7ffc-8699-7f99aa9f0ad4" 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_019ea99f-cc26-725f-826f-090140c6ce98" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_019ea99f-cc26-7ffc-8699-7f99aa9f0ad4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019ea99f-cc26-75ab-ab22-484082fb4ccd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfIncomeLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_019ea99f-cc26-7ffc-8699-7f99aa9f0ad4" xlink:to="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019ea99f-cc26-75ab-ab22-484082fb4ccd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_019ea99f-cc26-730b-93b9-350adb9451c6" 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_019ea99f-cc26-7ffc-8699-7f99aa9f0ad4" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_019ea99f-cc26-730b-93b9-350adb9451c6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_019ea99f-cc26-730b-93b9-350adb9451c6_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_019ea99f-cc26-730b-93b9-350adb9451c6" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_019ea99f-cc26-730b-93b9-350adb9451c6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_019ea99f-cc26-7d83-b760-3197a5c1c453" 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_019ea99f-cc26-730b-93b9-350adb9451c6" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_019ea99f-cc26-7d83-b760-3197a5c1c453" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_019ea99f-cc26-7457-937a-75311b6812af" 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_019ea99f-cc26-7d83-b760-3197a5c1c453" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_019ea99f-cc26-7457-937a-75311b6812af" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_019ea99f-cc26-7383-b987-2f98e39e666f" 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_019ea99f-cc26-7d83-b760-3197a5c1c453" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_019ea99f-cc26-7383-b987-2f98e39e666f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_019ea99f-cc26-79dd-8625-ecf1ad57d4ce" 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_DefinedBenefitPlanDisclosureLineItems_019ea99f-cc26-725f-826f-090140c6ce98" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_019ea99f-cc26-79dd-8625-ecf1ad57d4ce" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_019ea99f-cc26-7f5c-af93-66dea059810e" 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_DefinedBenefitPlanDisclosureLineItems_019ea99f-cc26-725f-826f-090140c6ce98" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_019ea99f-cc26-7f5c-af93-66dea059810e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_019ea99f-cc26-7230-ab90-9662fbeda6d9" 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_DefinedBenefitPlanDisclosureLineItems_019ea99f-cc26-725f-826f-090140c6ce98" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_019ea99f-cc26-7230-ab90-9662fbeda6d9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_019ea99f-cc26-7c17-a689-a6321fa37f98" 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_DefinedBenefitPlanDisclosureLineItems_019ea99f-cc26-725f-826f-090140c6ce98" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_019ea99f-cc26-7c17-a689-a6321fa37f98" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_019ea99f-cc26-7aa0-a81d-ced7a7029bc2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019ea99f-cc26-725f-826f-090140c6ce98" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_019ea99f-cc26-7aa0-a81d-ced7a7029bc2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_019ea99f-cc26-72e9-9900-29793431fde8" 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_DefinedBenefitPlanDisclosureLineItems_019ea99f-cc26-725f-826f-090140c6ce98" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_019ea99f-cc26-72e9-9900-29793431fde8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionAndOtherPostretirementBenefitExpense_019ea99f-cc26-7459-b58b-410613930bb8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PensionAndOtherPostretirementBenefitExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019ea99f-cc26-725f-826f-090140c6ce98" xlink:to="loc_us-gaap_PensionAndOtherPostretirementBenefitExpense_019ea99f-cc26-7459-b58b-410613930bb8" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/PostretirementPlansComponentsofNetPeriodicBenefitCostDetails_1" xlink:type="simple" xlink:href="ba-20260630.xsd#PostretirementPlansComponentsofNetPeriodicBenefitCostDetails_1"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/PostretirementPlansComponentsofNetPeriodicBenefitCostDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019ea99f-cc26-725f-826f-090140c6ce98" 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_019ea99f-cc26-7ffc-8699-7f99aa9f0ad4" 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_019ea99f-cc26-725f-826f-090140c6ce98" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_019ea99f-cc26-7ffc-8699-7f99aa9f0ad4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_019ea99f-cc26-730b-93b9-350adb9451c6" 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_019ea99f-cc26-7ffc-8699-7f99aa9f0ad4" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_019ea99f-cc26-730b-93b9-350adb9451c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_019ea99f-cc26-730b-93b9-350adb9451c6_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_019ea99f-cc26-730b-93b9-350adb9451c6" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_019ea99f-cc26-730b-93b9-350adb9451c6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_019ea99f-cc26-7d83-b760-3197a5c1c453" 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_019ea99f-cc26-730b-93b9-350adb9451c6" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_019ea99f-cc26-7d83-b760-3197a5c1c453" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_019ea99f-cc26-7457-937a-75311b6812af" 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_019ea99f-cc26-7d83-b760-3197a5c1c453" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_019ea99f-cc26-7457-937a-75311b6812af" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_019ea99f-cc26-7383-b987-2f98e39e666f" 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_019ea99f-cc26-7d83-b760-3197a5c1c453" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_019ea99f-cc26-7383-b987-2f98e39e666f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_019ea99f-cc26-79dd-8625-ecf1ad57d4ce" 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_DefinedBenefitPlanDisclosureLineItems_019ea99f-cc26-725f-826f-090140c6ce98" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_019ea99f-cc26-79dd-8625-ecf1ad57d4ce" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_019ea99f-cc26-7f5c-af93-66dea059810e" 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_DefinedBenefitPlanDisclosureLineItems_019ea99f-cc26-725f-826f-090140c6ce98" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_019ea99f-cc26-7f5c-af93-66dea059810e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_019ea99f-cc26-7230-ab90-9662fbeda6d9" 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_DefinedBenefitPlanDisclosureLineItems_019ea99f-cc26-725f-826f-090140c6ce98" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_019ea99f-cc26-7230-ab90-9662fbeda6d9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_019ea99f-cc26-7c17-a689-a6321fa37f98" 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_DefinedBenefitPlanDisclosureLineItems_019ea99f-cc26-725f-826f-090140c6ce98" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_019ea99f-cc26-7c17-a689-a6321fa37f98" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_019ea99f-cc26-7aa0-a81d-ced7a7029bc2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019ea99f-cc26-725f-826f-090140c6ce98" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_019ea99f-cc26-7aa0-a81d-ced7a7029bc2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_019ea99f-cc26-72e9-9900-29793431fde8" 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_DefinedBenefitPlanDisclosureLineItems_019ea99f-cc26-725f-826f-090140c6ce98" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_019ea99f-cc26-72e9-9900-29793431fde8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionAndOtherPostretirementBenefitExpense_019ea99f-cc26-7459-b58b-410613930bb8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PensionAndOtherPostretirementBenefitExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_019ea99f-cc26-725f-826f-090140c6ce98" xlink:to="loc_us-gaap_PensionAndOtherPostretirementBenefitExpense_019ea99f-cc26-7459-b58b-410613930bb8" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/ShareBasedCompensationandOtherCompensationArrangementsDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#ShareBasedCompensationandOtherCompensationArrangementsDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/ShareBasedCompensationandOtherCompensationArrangementsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ea99f-cc26-7748-b229-089af3bbcfdf" 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_019ea99f-cc26-79d3-ab0a-a57451e2d9a3" 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_019ea99f-cc26-7748-b229-089af3bbcfdf" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019ea99f-cc26-79d3-ab0a-a57451e2d9a3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019ea99f-cc26-7722-8539-0426bfdc4246" 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_019ea99f-cc26-79d3-ab0a-a57451e2d9a3" xlink:to="loc_us-gaap_AwardTypeAxis_019ea99f-cc26-7722-8539-0426bfdc4246" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ea99f-cc26-7722-8539-0426bfdc4246_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_019ea99f-cc26-7722-8539-0426bfdc4246" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ea99f-cc26-7722-8539-0426bfdc4246_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ea99f-cc26-76f6-a098-5f146ff5a4e3" 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_019ea99f-cc26-7722-8539-0426bfdc4246" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019ea99f-cc26-76f6-a098-5f146ff5a4e3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019ea99f-cc26-7e9a-b023-0325f321b89d" 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_019ea99f-cc26-76f6-a098-5f146ff5a4e3" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019ea99f-cc26-7e9a-b023-0325f321b89d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019ea99f-cc26-7fec-bdf3-1c23ab7ddbd9" 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_019ea99f-cc26-7748-b229-089af3bbcfdf" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019ea99f-cc26-7fec-bdf3-1c23ab7ddbd9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019ea99f-cc26-7f7c-bb59-1bf8ed1ee499" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ea99f-cc26-7748-b229-089af3bbcfdf" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019ea99f-cc26-7f7c-bb59-1bf8ed1ee499" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfEqualInstallments_019ea99f-cc26-7c85-b555-ce85d0831175" xlink:href="ba-20260630.xsd#ba_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfEqualInstallments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ea99f-cc26-7748-b229-089af3bbcfdf" xlink:to="loc_ba_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfEqualInstallments_019ea99f-cc26-7c85-b555-ce85d0831175" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityNoteStockSplitConversionRatio1_019ea99f-cc26-784c-8488-67f50200d858" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityNoteStockSplitConversionRatio1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019ea99f-cc26-7748-b229-089af3bbcfdf" xlink:to="loc_us-gaap_StockholdersEquityNoteStockSplitConversionRatio1_019ea99f-cc26-784c-8488-67f50200d858" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/ShareholdersEquityNarrativeDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#ShareholdersEquityNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/ShareholdersEquityNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_019ea99f-cc26-7e26-b773-623236c5468e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_019ea99f-cc26-7d68-ba53-ba796686ac28" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_019ea99f-cc26-7e26-b773-623236c5468e" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_019ea99f-cc26-7d68-ba53-ba796686ac28" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cc26-7696-ba5b-f243e63d875a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019ea99f-cc26-7d68-ba53-ba796686ac28" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cc26-7696-ba5b-f243e63d875a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019ea99f-cc26-7696-ba5b-f243e63d875a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cc26-7696-ba5b-f243e63d875a" xlink:to="loc_us-gaap_ClassOfStockDomain_019ea99f-cc26-7696-ba5b-f243e63d875a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019ea99f-cc26-79d2-989a-2ad5630786b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cc26-7696-ba5b-f243e63d875a" xlink:to="loc_us-gaap_ClassOfStockDomain_019ea99f-cc26-79d2-989a-2ad5630786b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_DepositaryShareMember_019ea99f-cc26-79bc-93de-93c271f59a0e" xlink:href="ba-20260630.xsd#ba_DepositaryShareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019ea99f-cc26-79d2-989a-2ad5630786b5" xlink:to="loc_ba_DepositaryShareMember_019ea99f-cc26-79bc-93de-93c271f59a0e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertiblePreferredStockMember_019ea99f-cc26-785d-83d9-371f4b532015" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConvertiblePreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019ea99f-cc26-79d2-989a-2ad5630786b5" xlink:to="loc_us-gaap_ConvertiblePreferredStockMember_019ea99f-cc26-785d-83d9-371f4b532015" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019ea99f-cc26-7268-a452-43f97e958ab3" 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_ScheduleOfStockByClassTable_019ea99f-cc26-7d68-ba53-ba796686ac28" xlink:to="loc_srt_RangeAxis_019ea99f-cc26-7268-a452-43f97e958ab3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019ea99f-cc26-7268-a452-43f97e958ab3_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_019ea99f-cc26-7268-a452-43f97e958ab3" xlink:to="loc_srt_RangeMember_019ea99f-cc26-7268-a452-43f97e958ab3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019ea99f-cc26-7324-b2b6-04f0bc90ecb5" 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_019ea99f-cc26-7268-a452-43f97e958ab3" xlink:to="loc_srt_RangeMember_019ea99f-cc26-7324-b2b6-04f0bc90ecb5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019ea99f-cc26-7bfa-9528-3d0f7f4302cb" 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_019ea99f-cc26-7324-b2b6-04f0bc90ecb5" xlink:to="loc_srt_MinimumMember_019ea99f-cc26-7bfa-9528-3d0f7f4302cb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019ea99f-cc26-7b34-b1e4-aabb5d6c935d" 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_019ea99f-cc26-7324-b2b6-04f0bc90ecb5" xlink:to="loc_srt_MaximumMember_019ea99f-cc26-7b34-b1e4-aabb5d6c935d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementScenarioAxis_019ea99f-cc26-7a8e-8f8e-261ce5bebafe" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StatementScenarioAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019ea99f-cc26-7d68-ba53-ba796686ac28" xlink:to="loc_srt_StatementScenarioAxis_019ea99f-cc26-7a8e-8f8e-261ce5bebafe" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_019ea99f-cc26-7a8e-8f8e-261ce5bebafe_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementScenarioAxis_019ea99f-cc26-7a8e-8f8e-261ce5bebafe" xlink:to="loc_srt_ScenarioUnspecifiedDomain_019ea99f-cc26-7a8e-8f8e-261ce5bebafe_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_019ea99f-cc26-7481-b2d1-ca161e824ec5" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementScenarioAxis_019ea99f-cc26-7a8e-8f8e-261ce5bebafe" xlink:to="loc_srt_ScenarioUnspecifiedDomain_019ea99f-cc26-7481-b2d1-ca161e824ec5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioForecastMember_019ea99f-cc26-789e-b7c9-f5acc03a6a8c" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScenarioForecastMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ScenarioUnspecifiedDomain_019ea99f-cc26-7481-b2d1-ca161e824ec5" xlink:to="loc_srt_ScenarioForecastMember_019ea99f-cc26-789e-b7c9-f5acc03a6a8c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_019ea99f-cc26-7bf1-bf33-cfe75227b2f9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019ea99f-cc26-7e26-b773-623236c5468e" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_019ea99f-cc26-7bf1-bf33-cfe75227b2f9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_019ea99f-cc26-7870-9d32-e0618e2c9da2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019ea99f-cc26-7e26-b773-623236c5468e" xlink:to="loc_us-gaap_PreferredStockSharesIssued_019ea99f-cc26-7870-9d32-e0618e2c9da2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendRatePercentage_019ea99f-cc26-708a-a9a3-7234e0e049dd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockDividendRatePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019ea99f-cc26-7e26-b773-623236c5468e" xlink:to="loc_us-gaap_PreferredStockDividendRatePercentage_019ea99f-cc26-708a-a9a3-7234e0e049dd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockLiquidationPreference_019ea99f-cc26-7dae-8d7f-9b2ee5b7ee6f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockLiquidationPreference"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019ea99f-cc26-7e26-b773-623236c5468e" xlink:to="loc_us-gaap_PreferredStockLiquidationPreference_019ea99f-cc26-7dae-8d7f-9b2ee5b7ee6f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_019ea99f-cc26-71ab-ac86-bc64d434fc91" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019ea99f-cc26-7e26-b773-623236c5468e" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_019ea99f-cc26-71ab-ac86-bc64d434fc91" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_019ea99f-cc26-768d-9360-baf08595f0d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019ea99f-cc26-7e26-b773-623236c5468e" xlink:to="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_019ea99f-cc26-768d-9360-baf08595f0d2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividends_019ea99f-cc26-7218-a20d-0eb4cb75c725" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsOfDividends"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019ea99f-cc26-7e26-b773-623236c5468e" xlink:to="loc_us-gaap_PaymentsOfDividends_019ea99f-cc26-7218-a20d-0eb4cb75c725" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPreferredStock_019ea99f-cc26-7747-9a9b-dd49f9dfdc05" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsPreferredStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019ea99f-cc26-7e26-b773-623236c5468e" xlink:to="loc_us-gaap_DividendsPreferredStock_019ea99f-cc26-7747-9a9b-dd49f9dfdc05" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendsPerShareDeclared_019ea99f-cc26-7c00-8c0e-eefb6ab06d6c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockDividendsPerShareDeclared"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019ea99f-cc26-7e26-b773-623236c5468e" xlink:to="loc_us-gaap_PreferredStockDividendsPerShareDeclared_019ea99f-cc26-7c00-8c0e-eefb6ab06d6c" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConversionOfStockSharesConverted1_019ea99f-cc26-7c13-b960-cb795adbb78e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConversionOfStockSharesConverted1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019ea99f-cc26-7e26-b773-623236c5468e" xlink:to="loc_us-gaap_ConversionOfStockSharesConverted1_019ea99f-cc26-7c13-b960-cb795adbb78e" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_EquityInstrumentConvertibleThresholdConsecutiveTradingDays_019ea99f-cc26-79b0-a2bb-e03acab25dad" xlink:href="ba-20260630.xsd#ba_EquityInstrumentConvertibleThresholdConsecutiveTradingDays"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019ea99f-cc26-7e26-b773-623236c5468e" xlink:to="loc_ba_EquityInstrumentConvertibleThresholdConsecutiveTradingDays_019ea99f-cc26-79b0-a2bb-e03acab25dad" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_EquityInstrumentConvertibleThresholdConsecutiveTradingDaysTriggerPeriod_019ea99f-cc26-7b33-8480-b45e9c7ae920" xlink:href="ba-20260630.xsd#ba_EquityInstrumentConvertibleThresholdConsecutiveTradingDaysTriggerPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019ea99f-cc26-7e26-b773-623236c5468e" xlink:to="loc_ba_EquityInstrumentConvertibleThresholdConsecutiveTradingDaysTriggerPeriod_019ea99f-cc26-7b33-8480-b45e9c7ae920" xlink:type="arc" order="11"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/ShareholdersEquityScheduleofConversionRatePerShareofMandatoryConvertiblePreferredStockDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#ShareholdersEquityScheduleofConversionRatePerShareofMandatoryConvertiblePreferredStockDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/ShareholdersEquityScheduleofConversionRatePerShareofMandatoryConvertiblePreferredStockDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_019ea99f-cc26-7feb-bdb7-8ed3d786ee14" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_019ea99f-cc26-71bd-b661-536d6d7ee0b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_019ea99f-cc26-7feb-bdb7-8ed3d786ee14" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_019ea99f-cc26-71bd-b661-536d6d7ee0b5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConversionOfStockByUniqueDescriptionAxis_019ea99f-cc26-7fda-aba8-0a8365680273" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConversionOfStockByUniqueDescriptionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019ea99f-cc26-71bd-b661-536d6d7ee0b5" xlink:to="loc_us-gaap_ConversionOfStockByUniqueDescriptionAxis_019ea99f-cc26-7fda-aba8-0a8365680273" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConversionOfStockNameDomain_019ea99f-cc26-7fda-aba8-0a8365680273_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConversionOfStockNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConversionOfStockByUniqueDescriptionAxis_019ea99f-cc26-7fda-aba8-0a8365680273" xlink:to="loc_us-gaap_ConversionOfStockNameDomain_019ea99f-cc26-7fda-aba8-0a8365680273_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConversionOfStockNameDomain_019ea99f-cc26-7a8d-ba60-c64a7af32be8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConversionOfStockNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConversionOfStockByUniqueDescriptionAxis_019ea99f-cc26-7fda-aba8-0a8365680273" xlink:to="loc_us-gaap_ConversionOfStockNameDomain_019ea99f-cc26-7a8d-ba60-c64a7af32be8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_StockConversionScenarioOneMember_019ea99f-cc26-7c71-a82e-00b1525f0f5c" xlink:href="ba-20260630.xsd#ba_StockConversionScenarioOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConversionOfStockNameDomain_019ea99f-cc26-7a8d-ba60-c64a7af32be8" xlink:to="loc_ba_StockConversionScenarioOneMember_019ea99f-cc26-7c71-a82e-00b1525f0f5c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_StockConversionScenarioTwoAndThreeMember_019ea99f-cc26-751b-8b90-18cf2846d79b" xlink:href="ba-20260630.xsd#ba_StockConversionScenarioTwoAndThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConversionOfStockNameDomain_019ea99f-cc26-7a8d-ba60-c64a7af32be8" xlink:to="loc_ba_StockConversionScenarioTwoAndThreeMember_019ea99f-cc26-751b-8b90-18cf2846d79b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_StockConversionScenarioTwoMember_019ea99f-cc26-76ae-984b-53b8061d788f" xlink:href="ba-20260630.xsd#ba_StockConversionScenarioTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_StockConversionScenarioTwoAndThreeMember_019ea99f-cc26-751b-8b90-18cf2846d79b" xlink:to="loc_ba_StockConversionScenarioTwoMember_019ea99f-cc26-76ae-984b-53b8061d788f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_StockConversionScenarioThreeMember_019ea99f-cc26-7fa7-9ae6-3728d76c89bc" xlink:href="ba-20260630.xsd#ba_StockConversionScenarioThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_StockConversionScenarioTwoAndThreeMember_019ea99f-cc26-751b-8b90-18cf2846d79b" xlink:to="loc_ba_StockConversionScenarioThreeMember_019ea99f-cc26-7fa7-9ae6-3728d76c89bc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_StockConversionScenarioFourMember_019ea99f-cc26-7376-9413-c7a6aa872c4d" xlink:href="ba-20260630.xsd#ba_StockConversionScenarioFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConversionOfStockNameDomain_019ea99f-cc26-7a8d-ba60-c64a7af32be8" xlink:to="loc_ba_StockConversionScenarioFourMember_019ea99f-cc26-7376-9413-c7a6aa872c4d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cc26-7c1c-8392-4bd46486da37" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019ea99f-cc26-71bd-b661-536d6d7ee0b5" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cc26-7c1c-8392-4bd46486da37" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019ea99f-cc26-7c1c-8392-4bd46486da37_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cc26-7c1c-8392-4bd46486da37" xlink:to="loc_us-gaap_ClassOfStockDomain_019ea99f-cc26-7c1c-8392-4bd46486da37_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019ea99f-cc26-7ff3-af42-d47b8a5788ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019ea99f-cc26-7c1c-8392-4bd46486da37" xlink:to="loc_us-gaap_ClassOfStockDomain_019ea99f-cc26-7ff3-af42-d47b8a5788ea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertiblePreferredStockMember_019ea99f-cc26-7e93-a4c8-0772ad2dfa40" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConvertiblePreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019ea99f-cc26-7ff3-af42-d47b8a5788ea" xlink:to="loc_us-gaap_ConvertiblePreferredStockMember_019ea99f-cc26-7e93-a4c8-0772ad2dfa40" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019ea99f-cc26-7860-990b-767e8b2fc039" 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_ScheduleOfStockByClassTable_019ea99f-cc26-71bd-b661-536d6d7ee0b5" xlink:to="loc_srt_RangeAxis_019ea99f-cc26-7860-990b-767e8b2fc039" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019ea99f-cc26-7860-990b-767e8b2fc039_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_019ea99f-cc26-7860-990b-767e8b2fc039" xlink:to="loc_srt_RangeMember_019ea99f-cc26-7860-990b-767e8b2fc039_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019ea99f-cc26-73c1-bf20-45211ac0626e" 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_019ea99f-cc26-7860-990b-767e8b2fc039" xlink:to="loc_srt_RangeMember_019ea99f-cc26-73c1-bf20-45211ac0626e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019ea99f-cc26-7d1e-80f3-5f9be9634e85" 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_019ea99f-cc26-73c1-bf20-45211ac0626e" xlink:to="loc_srt_MinimumMember_019ea99f-cc26-7d1e-80f3-5f9be9634e85" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019ea99f-cc26-78f0-9e1e-62b02833d2e2" 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_019ea99f-cc26-73c1-bf20-45211ac0626e" xlink:to="loc_srt_MaximumMember_019ea99f-cc26-78f0-9e1e-62b02833d2e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockConvertibleConversionPrice_019ea99f-cc26-7f40-bbdb-24d1a557866f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockConvertibleConversionPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019ea99f-cc26-7feb-bdb7-8ed3d786ee14" xlink:to="loc_us-gaap_PreferredStockConvertibleConversionPrice_019ea99f-cc26-7f40-bbdb-24d1a557866f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConversionOfStockSharesConverted1_019ea99f-cc26-77ad-b029-54548dd83bfe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConversionOfStockSharesConverted1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019ea99f-cc26-7feb-bdb7-8ed3d786ee14" xlink:to="loc_us-gaap_ConversionOfStockSharesConverted1_019ea99f-cc26-77ad-b029-54548dd83bfe" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/ShareholdersEquityScheduleofAccumulatedOtherComprehensiveIncomeLossDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#ShareholdersEquityScheduleofAccumulatedOtherComprehensiveIncomeLossDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/ShareholdersEquityScheduleofAccumulatedOtherComprehensiveIncomeLossDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019ea99f-cc26-791a-b138-2094961a8096" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019ea99f-cc26-7f3f-988b-40e6352f4e7a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019ea99f-cc26-791a-b138-2094961a8096" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_019ea99f-cc26-7f3f-988b-40e6352f4e7a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019ea99f-cc26-74c9-ad6c-92bd5644294f" 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_AccumulatedOtherComprehensiveIncomeLossTable_019ea99f-cc26-7f3f-988b-40e6352f4e7a" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019ea99f-cc26-74c9-ad6c-92bd5644294f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019ea99f-cc26-74c9-ad6c-92bd5644294f_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_019ea99f-cc26-74c9-ad6c-92bd5644294f" xlink:to="loc_us-gaap_EquityComponentDomain_019ea99f-cc26-74c9-ad6c-92bd5644294f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019ea99f-cc26-7ca3-8ea9-7678d8603b53" 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_019ea99f-cc26-74c9-ad6c-92bd5644294f" xlink:to="loc_us-gaap_EquityComponentDomain_019ea99f-cc26-7ca3-8ea9-7678d8603b53" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ea99f-cc26-761b-9543-839509c1f0ce" 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_019ea99f-cc26-7ca3-8ea9-7678d8603b53" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ea99f-cc26-761b-9543-839509c1f0ce" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019ea99f-cc26-776c-84d1-f27ed9ba0251" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ea99f-cc26-761b-9543-839509c1f0ce" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019ea99f-cc26-776c-84d1-f27ed9ba0251" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_019ea99f-cc26-73b6-b8f9-96db87b41f67" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ea99f-cc26-761b-9543-839509c1f0ce" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_019ea99f-cc26-73b6-b8f9-96db87b41f67" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019ea99f-cc26-7bff-8d6a-95d563ae1bd6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ea99f-cc26-761b-9543-839509c1f0ce" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019ea99f-cc26-7bff-8d6a-95d563ae1bd6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_019ea99f-cc26-768e-ab32-2bdfe7ded665" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019ea99f-cc26-761b-9543-839509c1f0ce" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_019ea99f-cc26-768e-ab32-2bdfe7ded665" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AccumulatedOtherComprehensiveIncomeLossRollForward_019ea99f-cc26-7d6c-bbef-c75677ab0398" xlink:href="ba-20260630.xsd#ba_AccumulatedOtherComprehensiveIncomeLossRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_019ea99f-cc26-791a-b138-2094961a8096" xlink:to="loc_ba_AccumulatedOtherComprehensiveIncomeLossRollForward_019ea99f-cc26-7d6c-bbef-c75677ab0398" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019ea99f-cc26-7516-96cb-9542f62ea435" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_AccumulatedOtherComprehensiveIncomeLossRollForward_019ea99f-cc26-7d6c-bbef-c75677ab0398" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019ea99f-cc26-7516-96cb-9542f62ea435" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_019ea99f-cc26-7886-a305-fb4b97b4a5eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_AccumulatedOtherComprehensiveIncomeLossRollForward_019ea99f-cc26-7d6c-bbef-c75677ab0398" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_019ea99f-cc26-7886-a305-fb4b97b4a5eb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_019ea99f-cc26-7b6e-85c4-60d6f0610967" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_AccumulatedOtherComprehensiveIncomeLossRollForward_019ea99f-cc26-7d6c-bbef-c75677ab0398" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_019ea99f-cc26-7b6e-85c4-60d6f0610967" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019ea99f-cc26-7af9-8f90-e877e0dbc2bc" 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_ba_AccumulatedOtherComprehensiveIncomeLossRollForward_019ea99f-cc26-7d6c-bbef-c75677ab0398" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019ea99f-cc26-7af9-8f90-e877e0dbc2bc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019ea99f-cc26-76eb-9eb3-d48e9c29565b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/DerivativeFinancialInstrumentsScheduleofDerivativeInstrumentsinStatementofFinancialPositionFairValueDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#DerivativeFinancialInstrumentsScheduleofDerivativeInstrumentsinStatementofFinancialPositionFairValueDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/DerivativeFinancialInstrumentsScheduleofDerivativeInstrumentsinStatementofFinancialPositionFairValueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_019ea99f-cc26-7b76-ba29-6e15dc3b09cb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019ea99f-cc26-7412-a3f2-ad54ef89ca8e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_019ea99f-cc26-7b76-ba29-6e15dc3b09cb" xlink:to="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019ea99f-cc26-7412-a3f2-ad54ef89ca8e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_019ea99f-cc26-72c6-adc5-7946ecf6a638" 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_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019ea99f-cc26-7412-a3f2-ad54ef89ca8e" xlink:to="loc_us-gaap_HedgingDesignationAxis_019ea99f-cc26-72c6-adc5-7946ecf6a638" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019ea99f-cc26-72c6-adc5-7946ecf6a638_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_019ea99f-cc26-72c6-adc5-7946ecf6a638" xlink:to="loc_us-gaap_HedgingDesignationDomain_019ea99f-cc26-72c6-adc5-7946ecf6a638_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019ea99f-cc26-7288-ae60-3cb2240e5127" 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_019ea99f-cc26-72c6-adc5-7946ecf6a638" xlink:to="loc_us-gaap_HedgingDesignationDomain_019ea99f-cc26-7288-ae60-3cb2240e5127" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019ea99f-cc26-7719-9f21-32e2f1968e93" 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_019ea99f-cc26-7288-ae60-3cb2240e5127" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019ea99f-cc26-7719-9f21-32e2f1968e93" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_019ea99f-cc26-7ce1-9038-109fab77d87b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019ea99f-cc26-7288-ae60-3cb2240e5127" xlink:to="loc_us-gaap_NondesignatedMember_019ea99f-cc26-7ce1-9038-109fab77d87b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019ea99f-cc26-7a7f-8096-3fe604f4d2b7" 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_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019ea99f-cc26-7412-a3f2-ad54ef89ca8e" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019ea99f-cc26-7a7f-8096-3fe604f4d2b7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019ea99f-cc26-7a7f-8096-3fe604f4d2b7_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_019ea99f-cc26-7a7f-8096-3fe604f4d2b7" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019ea99f-cc26-7a7f-8096-3fe604f4d2b7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019ea99f-cc26-7c45-a772-1e77a2ba182d" 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_019ea99f-cc26-7a7f-8096-3fe604f4d2b7" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019ea99f-cc26-7c45-a772-1e77a2ba182d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_019ea99f-cc26-7597-a3b9-db3a0cbb535a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019ea99f-cc26-7c45-a772-1e77a2ba182d" xlink:to="loc_us-gaap_ForeignExchangeContractMember_019ea99f-cc26-7597-a3b9-db3a0cbb535a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommodityContractMember_019ea99f-cc26-750b-a2c3-fc2cb049215b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommodityContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019ea99f-cc26-7c45-a772-1e77a2ba182d" xlink:to="loc_us-gaap_CommodityContractMember_019ea99f-cc26-750b-a2c3-fc2cb049215b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_019ea99f-cc26-752c-a64f-4d6deb6142c4" 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_DerivativeLineItems_019ea99f-cc26-7b76-ba29-6e15dc3b09cb" xlink:to="loc_us-gaap_DerivativeNotionalAmount_019ea99f-cc26-752c-a64f-4d6deb6142c4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement_019ea99f-cc26-7b3f-89e0-471cba6f4d55" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019ea99f-cc26-7b76-ba29-6e15dc3b09cb" xlink:to="loc_us-gaap_DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement_019ea99f-cc26-7b3f-89e0-471cba6f4d55" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement_019ea99f-cc26-770e-bbc1-e240ac89f073" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019ea99f-cc26-7b76-ba29-6e15dc3b09cb" xlink:to="loc_us-gaap_DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement_019ea99f-cc26-770e-bbc1-e240ac89f073" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetCollateralObligationToReturnCashOffset_019ea99f-cc26-731f-bc61-7b43e031755e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssetCollateralObligationToReturnCashOffset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019ea99f-cc26-7b76-ba29-6e15dc3b09cb" xlink:to="loc_us-gaap_DerivativeAssetCollateralObligationToReturnCashOffset_019ea99f-cc26-731f-bc61-7b43e031755e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityCollateralRightToReclaimCashOffset_019ea99f-cc26-7117-83b5-8ba8a53274dd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilityCollateralRightToReclaimCashOffset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019ea99f-cc26-7b76-ba29-6e15dc3b09cb" xlink:to="loc_us-gaap_DerivativeLiabilityCollateralRightToReclaimCashOffset_019ea99f-cc26-7117-83b5-8ba8a53274dd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_019ea99f-cc26-7b79-bdb1-ec9500f21d05" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019ea99f-cc26-7b76-ba29-6e15dc3b09cb" xlink:to="loc_us-gaap_DerivativeAssets_019ea99f-cc26-7b79-bdb1-ec9500f21d05" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_019ea99f-cc26-7b7d-89fb-cc3ae48f2c73" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019ea99f-cc26-7b76-ba29-6e15dc3b09cb" xlink:to="loc_us-gaap_DerivativeLiabilities_019ea99f-cc26-7b7d-89fb-cc3ae48f2c73" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetStatementOfFinancialPositionExtensibleEnumeration_019ea99f-cc26-7fb0-a5a0-fd756b445b3a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssetStatementOfFinancialPositionExtensibleEnumeration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019ea99f-cc26-7b76-ba29-6e15dc3b09cb" xlink:to="loc_us-gaap_DerivativeAssetStatementOfFinancialPositionExtensibleEnumeration_019ea99f-cc26-7fb0-a5a0-fd756b445b3a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityStatementOfFinancialPositionExtensibleEnumeration_019ea99f-cc26-77e5-bb40-4611992579e6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilityStatementOfFinancialPositionExtensibleEnumeration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019ea99f-cc26-7b76-ba29-6e15dc3b09cb" xlink:to="loc_us-gaap_DerivativeLiabilityStatementOfFinancialPositionExtensibleEnumeration_019ea99f-cc26-77e5-bb40-4611992579e6" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/DerivativeFinancialInstrumentsScheduleofDerivativeInstrumentsGainsLossesinStatementofFinancialPerformanceDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#DerivativeFinancialInstrumentsScheduleofDerivativeInstrumentsGainsLossesinStatementofFinancialPerformanceDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/DerivativeFinancialInstrumentsScheduleofDerivativeInstrumentsGainsLossesinStatementofFinancialPerformanceDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_019ea99f-cc26-789d-a29d-fbcb4f5494a7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_019ea99f-cc26-7cfe-bb98-4bed4e6215c1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_019ea99f-cc26-789d-a29d-fbcb4f5494a7" xlink:to="loc_us-gaap_DerivativeTable_019ea99f-cc26-7cfe-bb98-4bed4e6215c1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019ea99f-cc26-7011-a195-7605604ac9d3" 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_DerivativeTable_019ea99f-cc26-7cfe-bb98-4bed4e6215c1" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019ea99f-cc26-7011-a195-7605604ac9d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019ea99f-cc26-7011-a195-7605604ac9d3_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_019ea99f-cc26-7011-a195-7605604ac9d3" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019ea99f-cc26-7011-a195-7605604ac9d3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019ea99f-cc26-713c-90db-16776014135a" 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_019ea99f-cc26-7011-a195-7605604ac9d3" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019ea99f-cc26-713c-90db-16776014135a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_019ea99f-cc26-7791-ae49-160a0fa7e7a6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019ea99f-cc26-713c-90db-16776014135a" xlink:to="loc_us-gaap_ForeignExchangeContractMember_019ea99f-cc26-7791-ae49-160a0fa7e7a6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommodityContractMember_019ea99f-cc26-7a82-a1af-936713d89361" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommodityContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019ea99f-cc26-713c-90db-16776014135a" xlink:to="loc_us-gaap_CommodityContractMember_019ea99f-cc26-7a82-a1af-936713d89361" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax_019ea99f-cc26-7eff-8a7a-6a95313154f6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_019ea99f-cc26-789d-a29d-fbcb4f5494a7" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax_019ea99f-cc26-7eff-8a7a-6a95313154f6" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/DerivativeFinancialInstrumentsReclassificationOutofAccumulatedOtherComprehensiveIncomeDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#DerivativeFinancialInstrumentsReclassificationOutofAccumulatedOtherComprehensiveIncomeDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/DerivativeFinancialInstrumentsReclassificationOutofAccumulatedOtherComprehensiveIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeOnDerivativesLineItems_019f1f04-ae8d-7e41-981f-9463a4caeb88" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeOnDerivativesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_019ea99f-cc26-7f6c-89ea-9986f7621b79" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeOnDerivativesLineItems_019f1f04-ae8d-7e41-981f-9463a4caeb88" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_019ea99f-cc26-7f6c-89ea-9986f7621b79" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019f1f04-ae8d-7577-a5fc-496c8d99b6db" 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_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_019ea99f-cc26-7f6c-89ea-9986f7621b79" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019f1f04-ae8d-7577-a5fc-496c8d99b6db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019f1f04-ae8d-7577-a5fc-496c8d99b6db_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_019f1f04-ae8d-7577-a5fc-496c8d99b6db" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019f1f04-ae8d-7577-a5fc-496c8d99b6db_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019f1f04-ae8d-79d1-9b7a-e4259ca628ac" 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_019f1f04-ae8d-7577-a5fc-496c8d99b6db" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019f1f04-ae8d-79d1-9b7a-e4259ca628ac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_019f1f04-ae8d-7a0f-af56-608e5b913c64" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019f1f04-ae8d-79d1-9b7a-e4259ca628ac" xlink:to="loc_us-gaap_ForeignExchangeContractMember_019f1f04-ae8d-7a0f-af56-608e5b913c64" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommodityContractMember_019f1f04-ae8d-7e66-a5e9-dfb090236f88" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommodityContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019f1f04-ae8d-79d1-9b7a-e4259ca628ac" xlink:to="loc_us-gaap_CommodityContractMember_019f1f04-ae8d-7e66-a5e9-dfb090236f88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019f1f04-ae8d-7eb8-8349-24798a495e57" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfIncomeLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_019ea99f-cc26-7f6c-89ea-9986f7621b79" xlink:to="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019f1f04-ae8d-7eb8-8349-24798a495e57" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax_019f1f04-ae8d-7927-a427-cbcbff887649" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeOnDerivativesLineItems_019f1f04-ae8d-7e41-981f-9463a4caeb88" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax_019f1f04-ae8d-7927-a427-cbcbff887649" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/DerivativeFinancialInstrumentsReclassificationOutofAccumulatedOtherComprehensiveIncomeDetails_1" xlink:type="simple" xlink:href="ba-20260630.xsd#DerivativeFinancialInstrumentsReclassificationOutofAccumulatedOtherComprehensiveIncomeDetails_1"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/DerivativeFinancialInstrumentsReclassificationOutofAccumulatedOtherComprehensiveIncomeDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeOnDerivativesLineItems_019f1f04-ae8d-7e41-981f-9463a4caeb88" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeOnDerivativesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_019ea99f-cc26-7f6c-89ea-9986f7621b79" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeOnDerivativesLineItems_019f1f04-ae8d-7e41-981f-9463a4caeb88" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_019ea99f-cc26-7f6c-89ea-9986f7621b79" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019f1f04-ae8d-7577-a5fc-496c8d99b6db" 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_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_019ea99f-cc26-7f6c-89ea-9986f7621b79" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019f1f04-ae8d-7577-a5fc-496c8d99b6db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019f1f04-ae8d-7577-a5fc-496c8d99b6db_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_019f1f04-ae8d-7577-a5fc-496c8d99b6db" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019f1f04-ae8d-7577-a5fc-496c8d99b6db_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019f1f04-ae8d-79d1-9b7a-e4259ca628ac" 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_019f1f04-ae8d-7577-a5fc-496c8d99b6db" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019f1f04-ae8d-79d1-9b7a-e4259ca628ac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_019f1f04-ae8d-7a0f-af56-608e5b913c64" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019f1f04-ae8d-79d1-9b7a-e4259ca628ac" xlink:to="loc_us-gaap_ForeignExchangeContractMember_019f1f04-ae8d-7a0f-af56-608e5b913c64" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommodityContractMember_019f1f04-ae8d-7e66-a5e9-dfb090236f88" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommodityContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019f1f04-ae8d-79d1-9b7a-e4259ca628ac" xlink:to="loc_us-gaap_CommodityContractMember_019f1f04-ae8d-7e66-a5e9-dfb090236f88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax_019f1f04-ae8d-7927-a427-cbcbff887649" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeOnDerivativesLineItems_019f1f04-ae8d-7e41-981f-9463a4caeb88" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationBeforeTax_019f1f04-ae8d-7927-a427-cbcbff887649" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/FairValueMeasurementsFairValueAssetsandLiabilitiesMeasuredonRecurringBasisDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#FairValueMeasurementsFairValueAssetsandLiabilitiesMeasuredonRecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/FairValueMeasurementsFairValueAssetsandLiabilitiesMeasuredonRecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019ea99f-cc26-75f8-9ea4-edf3fa40a176" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019ea99f-cc26-71f5-851d-f6b65949a833" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019ea99f-cc26-75f8-9ea4-edf3fa40a176" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019ea99f-cc26-71f5-851d-f6b65949a833" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019ea99f-cc26-7472-b138-70397c1d51dc" 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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019ea99f-cc26-71f5-851d-f6b65949a833" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019ea99f-cc26-7472-b138-70397c1d51dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_019ea99f-cc26-7472-b138-70397c1d51dc_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_019ea99f-cc26-7472-b138-70397c1d51dc" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_019ea99f-cc26-7472-b138-70397c1d51dc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_019ea99f-cc26-7fe4-bbec-a38aef01d45d" 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_019ea99f-cc26-7472-b138-70397c1d51dc" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_019ea99f-cc26-7fe4-bbec-a38aef01d45d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_019ea99f-cc26-7f9a-b783-28f8b7debde7" 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_019ea99f-cc26-7fe4-bbec-a38aef01d45d" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_019ea99f-cc26-7f9a-b783-28f8b7debde7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019ea99f-cc26-7a46-9467-f14cae9ca2ef" 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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019ea99f-cc26-71f5-851d-f6b65949a833" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019ea99f-cc26-7a46-9467-f14cae9ca2ef" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ea99f-cc26-7a46-9467-f14cae9ca2ef_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_019ea99f-cc26-7a46-9467-f14cae9ca2ef" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ea99f-cc26-7a46-9467-f14cae9ca2ef_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ea99f-cc26-73bf-b1ba-d6a94d0904af" 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_019ea99f-cc26-7a46-9467-f14cae9ca2ef" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ea99f-cc26-73bf-b1ba-d6a94d0904af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_019ea99f-cc26-7198-8acc-1306f72a5a92" 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_019ea99f-cc26-73bf-b1ba-d6a94d0904af" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_019ea99f-cc26-7198-8acc-1306f72a5a92" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019ea99f-cc26-7b61-a2b8-8e49c7819686" 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_019ea99f-cc26-73bf-b1ba-d6a94d0904af" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019ea99f-cc26-7b61-a2b8-8e49c7819686" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_019ea99f-cc26-7479-a1a6-7b350fd85f88" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019ea99f-cc26-71f5-851d-f6b65949a833" xlink:to="loc_us-gaap_FinancialInstrumentAxis_019ea99f-cc26-7479-a1a6-7b350fd85f88" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ea99f-cc26-7479-a1a6-7b350fd85f88_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019ea99f-cc26-7479-a1a6-7b350fd85f88" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ea99f-cc26-7479-a1a6-7b350fd85f88_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ea99f-cc26-77a6-a72e-a2b71329c21c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019ea99f-cc26-7479-a1a6-7b350fd85f88" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ea99f-cc26-77a6-a72e-a2b71329c21c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperMember_019ea99f-cc26-7610-9275-7436a41e8aeb" 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_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ea99f-cc26-77a6-a72e-a2b71329c21c" xlink:to="loc_us-gaap_CommercialPaperMember_019ea99f-cc26-7610-9275-7436a41e8aeb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNoteSecuritiesMember_019ea99f-cc26-7212-bda1-f0b1f02cb6b4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateNoteSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ea99f-cc26-77a6-a72e-a2b71329c21c" xlink:to="loc_us-gaap_CorporateNoteSecuritiesMember_019ea99f-cc26-7212-bda1-f0b1f02cb6b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_019ea99f-cc26-7cc9-8078-a2fc4445568d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USGovernmentAgenciesDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019ea99f-cc26-77a6-a72e-a2b71329c21c" xlink:to="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_019ea99f-cc26-7cc9-8078-a2fc4445568d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_019ea99f-cc26-7b23-94a7-debdc594abb9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019ea99f-cc26-75f8-9ea4-edf3fa40a176" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_019ea99f-cc26-7b23-94a7-debdc594abb9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019ea99f-cc26-7480-acb4-a85826d90ee7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019ea99f-cc26-75f8-9ea4-edf3fa40a176" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019ea99f-cc26-7480-acb4-a85826d90ee7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherInvestments_019ea99f-cc26-762c-a0a5-ec4cf78b5e8f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019ea99f-cc26-75f8-9ea4-edf3fa40a176" xlink:to="loc_us-gaap_OtherInvestments_019ea99f-cc26-762c-a0a5-ec4cf78b5e8f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_019ea99f-cc26-7ea3-9cc6-0c80578dd589" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019ea99f-cc26-75f8-9ea4-edf3fa40a176" xlink:to="loc_us-gaap_DerivativeAssets_019ea99f-cc26-7ea3-9cc6-0c80578dd589" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_019ea99f-cc26-7efe-ae5e-d6e88d5ca12e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019ea99f-cc26-75f8-9ea4-edf3fa40a176" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_019ea99f-cc26-7efe-ae5e-d6e88d5ca12e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_019ea99f-cc26-71ee-9618-b2c42d3c3fe6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019ea99f-cc26-75f8-9ea4-edf3fa40a176" xlink:to="loc_us-gaap_DerivativeLiabilities_019ea99f-cc26-71ee-9618-b2c42d3c3fe6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_019ea99f-cc26-741d-ac86-93e7520e0de2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019ea99f-cc26-75f8-9ea4-edf3fa40a176" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosure_019ea99f-cc26-741d-ac86-93e7520e0de2" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/FairValueMeasurementsFairValueAssetsMeasuredonNonrecurringBasisUsingUnobservableInputsDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#FairValueMeasurementsFairValueAssetsMeasuredonNonrecurringBasisUsingUnobservableInputsDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/FairValueMeasurementsFairValueAssetsMeasuredonNonrecurringBasisUsingUnobservableInputsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019ea99f-cc26-7eb5-845d-3ec10c7181cf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019ea99f-cc26-78b5-b086-bd87c06e1687" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019ea99f-cc26-7eb5-845d-3ec10c7181cf" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019ea99f-cc26-78b5-b086-bd87c06e1687" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_019ea99f-cc26-768d-88a6-87775aaeffa3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByAssetClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019ea99f-cc26-78b5-b086-bd87c06e1687" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_019ea99f-cc26-768d-88a6-87775aaeffa3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019ea99f-cc26-768d-88a6-87775aaeffa3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_019ea99f-cc26-768d-88a6-87775aaeffa3" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019ea99f-cc26-768d-88a6-87775aaeffa3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019ea99f-cc26-7d6a-9b75-13b75613740e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_019ea99f-cc26-768d-88a6-87775aaeffa3" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019ea99f-cc26-7d6a-9b75-13b75613740e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsMember_019ea99f-cc26-74f8-b845-4bf52a3fb35a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019ea99f-cc26-7d6a-9b75-13b75613740e" xlink:to="loc_us-gaap_InvestmentsMember_019ea99f-cc26-74f8-b845-4bf52a3fb35a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_OtherAssetMember_019f1f08-9123-7531-9eb9-5dde7cc3ef9c" xlink:href="ba-20260630.xsd#ba_OtherAssetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019ea99f-cc26-7d6a-9b75-13b75613740e" xlink:to="loc_ba_OtherAssetMember_019f1f08-9123-7531-9eb9-5dde7cc3ef9c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_OperatingLeaseEquipmentAndAssetsHeldForSaleOrReLeaseMember_019ea99f-cc26-7cb1-8bbf-f969ce59f07c" xlink:href="ba-20260630.xsd#ba_OperatingLeaseEquipmentAndAssetsHeldForSaleOrReLeaseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019ea99f-cc26-7d6a-9b75-13b75613740e" xlink:to="loc_ba_OperatingLeaseEquipmentAndAssetsHeldForSaleOrReLeaseMember_019ea99f-cc26-7cb1-8bbf-f969ce59f07c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019ea99f-cc26-776d-8a92-d686db8ab4ea" 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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019ea99f-cc26-78b5-b086-bd87c06e1687" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019ea99f-cc26-776d-8a92-d686db8ab4ea" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_019ea99f-cc26-776d-8a92-d686db8ab4ea_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_019ea99f-cc26-776d-8a92-d686db8ab4ea" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_019ea99f-cc26-776d-8a92-d686db8ab4ea_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_019ea99f-cc26-78e6-a490-0434344c9295" 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_019ea99f-cc26-776d-8a92-d686db8ab4ea" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_019ea99f-cc26-78e6-a490-0434344c9295" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsNonrecurringMember_019ea99f-cc26-7562-b4ed-d96fdb9accec" 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_019ea99f-cc26-78e6-a490-0434344c9295" xlink:to="loc_us-gaap_FairValueMeasurementsNonrecurringMember_019ea99f-cc26-7562-b4ed-d96fdb9accec" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_019ea99f-cc26-7aec-802a-3ed450ea65e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019ea99f-cc26-7eb5-845d-3ec10c7181cf" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_019ea99f-cc26-7aec-802a-3ed450ea65e5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetImpairmentCharges_019ea99f-cc26-70ee-9559-af838fa4fdf2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetImpairmentCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019ea99f-cc26-7eb5-845d-3ec10c7181cf" xlink:to="loc_us-gaap_AssetImpairmentCharges_019ea99f-cc26-70ee-9559-af838fa4fdf2" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/FairValueMeasurementsFairValueAssetsMeasuredonNonrecurringBasisValuationTechniquesDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#FairValueMeasurementsFairValueAssetsMeasuredonNonrecurringBasisValuationTechniquesDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/FairValueMeasurementsFairValueAssetsMeasuredonNonrecurringBasisValuationTechniquesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019ea99f-cc26-7f34-bae4-5cd754777eb8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019ea99f-cc26-725c-946a-198ac82f9a29" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019ea99f-cc26-7f34-bae4-5cd754777eb8" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019ea99f-cc26-725c-946a-198ac82f9a29" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueAxis_019ea99f-cc26-7c2d-9e28-4e4595be649a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ValuationTechniqueAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019ea99f-cc26-725c-946a-198ac82f9a29" xlink:to="loc_us-gaap_ValuationTechniqueAxis_019ea99f-cc26-7c2d-9e28-4e4595be649a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_019ea99f-cc26-7c2d-9e28-4e4595be649a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationTechniqueAxis_019ea99f-cc26-7c2d-9e28-4e4595be649a" xlink:to="loc_us-gaap_ValuationTechniqueDomain_019ea99f-cc26-7c2d-9e28-4e4595be649a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_019ea99f-cc26-78b8-9b8c-80b6fd6e138d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationTechniqueAxis_019ea99f-cc26-7c2d-9e28-4e4595be649a" xlink:to="loc_us-gaap_ValuationTechniqueDomain_019ea99f-cc26-78b8-9b8c-80b6fd6e138d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketApproachValuationTechniqueMember_019ea99f-cc26-7663-a156-2646b9795c4d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MarketApproachValuationTechniqueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_019ea99f-cc26-78b8-9b8c-80b6fd6e138d" xlink:to="loc_us-gaap_MarketApproachValuationTechniqueMember_019ea99f-cc26-7663-a156-2646b9795c4d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019ea99f-cc26-723d-8acb-ccb9c89f1334" 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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019ea99f-cc26-725c-946a-198ac82f9a29" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019ea99f-cc26-723d-8acb-ccb9c89f1334" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ea99f-cc26-723d-8acb-ccb9c89f1334_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_019ea99f-cc26-723d-8acb-ccb9c89f1334" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ea99f-cc26-723d-8acb-ccb9c89f1334_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ea99f-cc26-7fe8-a64f-f9d08f2c5083" 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_019ea99f-cc26-723d-8acb-ccb9c89f1334" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ea99f-cc26-7fe8-a64f-f9d08f2c5083" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_019ea99f-cc26-7108-8e5f-433bb11ad5e6" 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_019ea99f-cc26-7fe8-a64f-f9d08f2c5083" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_019ea99f-cc26-7108-8e5f-433bb11ad5e6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019ea99f-cc26-77c0-87dc-a116faf384e1" 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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019ea99f-cc26-725c-946a-198ac82f9a29" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019ea99f-cc26-77c0-87dc-a116faf384e1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_019ea99f-cc26-77c0-87dc-a116faf384e1_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_019ea99f-cc26-77c0-87dc-a116faf384e1" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_019ea99f-cc26-77c0-87dc-a116faf384e1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_019ea99f-cc26-7533-b82f-129d2ececa7f" 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_019ea99f-cc26-77c0-87dc-a116faf384e1" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_019ea99f-cc26-7533-b82f-129d2ececa7f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsNonrecurringMember_019ea99f-cc26-7eae-8998-8a61a3c4a07e" 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_019ea99f-cc26-7533-b82f-129d2ececa7f" xlink:to="loc_us-gaap_FairValueMeasurementsNonrecurringMember_019ea99f-cc26-7eae-8998-8a61a3c4a07e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_019ea99f-cc26-713d-8fd8-8574de9c18e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByAssetClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019ea99f-cc26-725c-946a-198ac82f9a29" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_019ea99f-cc26-713d-8fd8-8574de9c18e1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019ea99f-cc26-713d-8fd8-8574de9c18e1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_019ea99f-cc26-713d-8fd8-8574de9c18e1" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019ea99f-cc26-713d-8fd8-8574de9c18e1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019ea99f-cc26-7abc-80b6-04c4162de989" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_019ea99f-cc26-713d-8fd8-8574de9c18e1" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019ea99f-cc26-7abc-80b6-04c4162de989" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_OperatingLeaseEquipmentAndAssetsHeldForSaleOrReLeaseMember_019ea99f-cc26-764e-a1fc-45462645e0e0" xlink:href="ba-20260630.xsd#ba_OperatingLeaseEquipmentAndAssetsHeldForSaleOrReLeaseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019ea99f-cc26-7abc-80b6-04c4162de989" xlink:to="loc_ba_OperatingLeaseEquipmentAndAssetsHeldForSaleOrReLeaseMember_019ea99f-cc26-764e-a1fc-45462645e0e0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019ea99f-cc26-7deb-8367-b8175263c064" 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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019ea99f-cc26-725c-946a-198ac82f9a29" xlink:to="loc_srt_RangeAxis_019ea99f-cc26-7deb-8367-b8175263c064" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019ea99f-cc26-7deb-8367-b8175263c064_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_019ea99f-cc26-7deb-8367-b8175263c064" xlink:to="loc_srt_RangeMember_019ea99f-cc26-7deb-8367-b8175263c064_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019ea99f-cc26-7c26-b99e-73f175dd1827" 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_019ea99f-cc26-7deb-8367-b8175263c064" xlink:to="loc_srt_RangeMember_019ea99f-cc26-7c26-b99e-73f175dd1827" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_019ea99f-cc26-7dac-8adc-502d3b571b39" 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_019ea99f-cc26-7c26-b99e-73f175dd1827" xlink:to="loc_srt_MinimumMember_019ea99f-cc26-7dac-8adc-502d3b571b39" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_019ea99f-cc26-7530-b080-56b5e7faa402" 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_019ea99f-cc26-7c26-b99e-73f175dd1827" xlink:to="loc_srt_MaximumMember_019ea99f-cc26-7530-b080-56b5e7faa402" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_019ea99f-cc26-73fd-a976-2b40482cd979" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_019ea99f-cc26-725c-946a-198ac82f9a29" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_019ea99f-cc26-73fd-a976-2b40482cd979" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_019ea99f-cc26-73fd-a976-2b40482cd979_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_019ea99f-cc26-73fd-a976-2b40482cd979" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_019ea99f-cc26-73fd-a976-2b40482cd979_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_019ea99f-cc26-7e01-a484-a1226dada75d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_019ea99f-cc26-73fd-a976-2b40482cd979" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_019ea99f-cc26-7e01-a484-a1226dada75d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AircraftValuePublicationsMember_019ea99f-cc26-7fe8-a03f-c07eee79b879" xlink:href="ba-20260630.xsd#ba_AircraftValuePublicationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_019ea99f-cc26-7e01-a484-a1226dada75d" xlink:to="loc_ba_AircraftValuePublicationsMember_019ea99f-cc26-7fe8-a03f-c07eee79b879" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_019ea99f-cc26-7355-9a0f-7da3542446ad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019ea99f-cc26-7f34-bae4-5cd754777eb8" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_019ea99f-cc26-7355-9a0f-7da3542446ad" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_RangeOfFairValueOfAssetsMeasuredOnNonrecurringBasisValuationTechniques_019ea99f-cc26-7150-8636-28e32c883f32" xlink:href="ba-20260630.xsd#ba_RangeOfFairValueOfAssetsMeasuredOnNonrecurringBasisValuationTechniques"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_019ea99f-cc26-7f34-bae4-5cd754777eb8" xlink:to="loc_ba_RangeOfFairValueOfAssetsMeasuredOnNonrecurringBasisValuationTechniques_019ea99f-cc26-7150-8636-28e32c883f32" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/FairValueMeasurementsFairValuesandRelatedCarryingValuesofFinancialInstrumentsDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#FairValueMeasurementsFairValuesandRelatedCarryingValuesofFinancialInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/FairValueMeasurementsFairValuesandRelatedCarryingValuesofFinancialInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_019ea99f-cc26-7e6e-aadb-9182bf366596" 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_019ea99f-cc26-74c8-93e6-d7db2defb689" 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_019ea99f-cc26-7e6e-aadb-9182bf366596" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_019ea99f-cc26-74c8-93e6-d7db2defb689" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019ea99f-cc26-78bb-85e1-dea5a257bcb7" 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_019ea99f-cc26-74c8-93e6-d7db2defb689" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019ea99f-cc26-78bb-85e1-dea5a257bcb7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ea99f-cc26-78bb-85e1-dea5a257bcb7_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_019ea99f-cc26-78bb-85e1-dea5a257bcb7" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ea99f-cc26-78bb-85e1-dea5a257bcb7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ea99f-cc26-714b-9153-486b6709025e" 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_019ea99f-cc26-78bb-85e1-dea5a257bcb7" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019ea99f-cc26-714b-9153-486b6709025e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019ea99f-cc26-7ccb-92b6-1a71d39756b9" 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_019ea99f-cc26-714b-9153-486b6709025e" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019ea99f-cc26-7ccb-92b6-1a71d39756b9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_019ea99f-cc26-74d5-8547-0154a110290b" 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_019ea99f-cc26-714b-9153-486b6709025e" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_019ea99f-cc26-74d5-8547-0154a110290b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableNet_019ea99f-cc26-7c4e-b9f7-e78363723d28" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesReceivableNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_019ea99f-cc26-7e6e-aadb-9182bf366596" xlink:to="loc_us-gaap_NotesReceivableNet_019ea99f-cc26-7c4e-b9f7-e78363723d28" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableFairValueDisclosure_019ea99f-cc26-7c3a-8712-a3ce8dc55280" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesReceivableFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_019ea99f-cc26-7e6e-aadb-9182bf366596" xlink:to="loc_us-gaap_NotesReceivableFairValueDisclosure_019ea99f-cc26-7c3a-8712-a3ce8dc55280" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019ea99f-cc26-76b2-bebd-5e9166f6bbbc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_019ea99f-cc26-7e6e-aadb-9182bf366596" xlink:to="loc_us-gaap_LongTermDebt_019ea99f-cc26-76b2-bebd-5e9166f6bbbc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFairValue_019ea99f-cc26-77d5-995e-94caf6618640" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_019ea99f-cc26-7e6e-aadb-9182bf366596" xlink:to="loc_us-gaap_DebtInstrumentFairValue_019ea99f-cc26-77d5-995e-94caf6618640" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/SegmentandRevenueInformationNarrativeDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#SegmentandRevenueInformationNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/SegmentandRevenueInformationNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc26-72a2-88d9-f499dc23bc82" 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_019ea99f-cc26-71f2-9ec9-8ee689cd72c1" 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_019ea99f-cc26-72a2-88d9-f499dc23bc82" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ea99f-cc26-71f2-9ec9-8ee689cd72c1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_FiscalYearAxis_019ea99f-cc26-78e8-9f6e-c116a9e44618" xlink:href="ba-20260630.xsd#ba_FiscalYearAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ea99f-cc26-71f2-9ec9-8ee689cd72c1" xlink:to="loc_ba_FiscalYearAxis_019ea99f-cc26-78e8-9f6e-c116a9e44618" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_FiscalYearDomain_019ea99f-cc26-78e8-9f6e-c116a9e44618_default" xlink:href="ba-20260630.xsd#ba_FiscalYearDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_ba_FiscalYearAxis_019ea99f-cc26-78e8-9f6e-c116a9e44618" xlink:to="loc_ba_FiscalYearDomain_019ea99f-cc26-78e8-9f6e-c116a9e44618_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_FiscalYearDomain_019ea99f-cc26-7b29-aebd-d5b753162c90" xlink:href="ba-20260630.xsd#ba_FiscalYearDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_ba_FiscalYearAxis_019ea99f-cc26-78e8-9f6e-c116a9e44618" xlink:to="loc_ba_FiscalYearDomain_019ea99f-cc26-7b29-aebd-d5b753162c90" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_WithinNextFiscalYearMember_019ea99f-cc26-7d4b-a97d-f0fd6e8e2ded" xlink:href="ba-20260630.xsd#ba_WithinNextFiscalYearMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_FiscalYearDomain_019ea99f-cc26-7b29-aebd-d5b753162c90" xlink:to="loc_ba_WithinNextFiscalYearMember_019ea99f-cc26-7d4b-a97d-f0fd6e8e2ded" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_WithinNextFourFiscalYearsMember_019ea99f-cc26-72a4-85a1-a610a28903e4" xlink:href="ba-20260630.xsd#ba_WithinNextFourFiscalYearsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_FiscalYearDomain_019ea99f-cc26-7b29-aebd-d5b753162c90" xlink:to="loc_ba_WithinNextFourFiscalYearsMember_019ea99f-cc26-72a4-85a1-a610a28903e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_019ea99f-cc26-7d74-8333-9a766a626b40" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc26-72a2-88d9-f499dc23bc82" xlink:to="loc_us-gaap_NumberOfReportableSegments_019ea99f-cc26-7d74-8333-9a766a626b40" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_019ea99f-cc26-7fdb-b55c-efcc3862709e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc26-72a2-88d9-f499dc23bc82" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_019ea99f-cc26-7fdb-b55c-efcc3862709e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_019ea99f-cc26-7b3a-9d66-de07aad95fbd" 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_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc26-72a2-88d9-f499dc23bc82" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_019ea99f-cc26-7b3a-9d66-de07aad95fbd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_RevenueRemainingPerformanceObligationPercentRecognized_019ea99f-cc26-708b-9307-2f4d41f5eca2" xlink:href="ba-20260630.xsd#ba_RevenueRemainingPerformanceObligationPercentRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc26-72a2-88d9-f499dc23bc82" xlink:to="loc_ba_RevenueRemainingPerformanceObligationPercentRecognized_019ea99f-cc26-708b-9307-2f4d41f5eca2" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/SegmentandRevenueInformationReconciliationofRevenuefromSegmentstoConsolidatedDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#SegmentandRevenueInformationReconciliationofRevenuefromSegmentstoConsolidatedDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/SegmentandRevenueInformationReconciliationofRevenuefromSegmentstoConsolidatedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc26-7593-a478-c173afdaba93" 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_019ea99f-cc26-7d22-9d8c-d9f4b1a723f4" 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_019ea99f-cc26-7593-a478-c173afdaba93" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ea99f-cc26-7d22-9d8c-d9f4b1a723f4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019ea99f-cc26-7053-b063-e369b8743359" 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_019ea99f-cc26-7d22-9d8c-d9f4b1a723f4" xlink:to="loc_srt_ConsolidationItemsAxis_019ea99f-cc26-7053-b063-e369b8743359" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ea99f-cc26-7053-b063-e369b8743359_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_019ea99f-cc26-7053-b063-e369b8743359" xlink:to="loc_srt_ConsolidationItemsDomain_019ea99f-cc26-7053-b063-e369b8743359_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ea99f-cc26-7c26-9613-5c906f9f8405" 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_019ea99f-cc26-7053-b063-e369b8743359" xlink:to="loc_srt_ConsolidationItemsDomain_019ea99f-cc26-7c26-9613-5c906f9f8405" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019ea99f-cc26-725b-a609-59ed5e2c778f" 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_019ea99f-cc26-7c26-9613-5c906f9f8405" xlink:to="loc_us-gaap_OperatingSegmentsMember_019ea99f-cc26-725b-a609-59ed5e2c778f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019ea99f-cc26-7ea0-926f-1fb2444fb3c1" 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_019ea99f-cc26-7d22-9d8c-d9f4b1a723f4" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019ea99f-cc26-7ea0-926f-1fb2444fb3c1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ea99f-cc26-7ea0-926f-1fb2444fb3c1_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_019ea99f-cc26-7ea0-926f-1fb2444fb3c1" xlink:to="loc_us-gaap_SegmentDomain_019ea99f-cc26-7ea0-926f-1fb2444fb3c1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ea99f-cc26-71e8-a23a-dd648c44dabf" 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_019ea99f-cc26-7ea0-926f-1fb2444fb3c1" xlink:to="loc_us-gaap_SegmentDomain_019ea99f-cc26-71e8-a23a-dd648c44dabf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommercialAirplanesSegmentMember_019ea99f-cc26-756c-be92-2bbdbea7bf63" xlink:href="ba-20260630.xsd#ba_CommercialAirplanesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cc26-71e8-a23a-dd648c44dabf" xlink:to="loc_ba_CommercialAirplanesSegmentMember_019ea99f-cc26-756c-be92-2bbdbea7bf63" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BoeingDefenseSpaceSecuritySegmentMember_019ea99f-cc26-719b-9d1f-302f8d508f52" xlink:href="ba-20260630.xsd#ba_BoeingDefenseSpaceSecuritySegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cc26-71e8-a23a-dd648c44dabf" xlink:to="loc_ba_BoeingDefenseSpaceSecuritySegmentMember_019ea99f-cc26-719b-9d1f-302f8d508f52" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_GlobalServicesMember_019ea99f-cc26-7587-b2b9-540b71e985b7" xlink:href="ba-20260630.xsd#ba_GlobalServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cc26-71e8-a23a-dd648c44dabf" xlink:to="loc_ba_GlobalServicesMember_019ea99f-cc26-7587-b2b9-540b71e985b7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019ea99f-cc26-71ef-917e-d4b20a79cdd7" 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_019ea99f-cc26-7593-a478-c173afdaba93" xlink:to="loc_us-gaap_Revenues_019ea99f-cc26-71ef-917e-d4b20a79cdd7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_019ea99f-cc26-765b-927f-c4b892b3668a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc26-7593-a478-c173afdaba93" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_019ea99f-cc26-765b-927f-c4b892b3668a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingOtherItemAmount_019ea99f-cc26-7bc1-ab48-b1727fd0c9d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingOtherItemAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc26-7593-a478-c173afdaba93" xlink:to="loc_us-gaap_SegmentReportingOtherItemAmount_019ea99f-cc26-7bc1-ab48-b1727fd0c9d0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019ea99f-cc26-76b3-8a5c-fa5a772df69f" 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_SegmentReportingInformationLineItems_019ea99f-cc26-7593-a478-c173afdaba93" xlink:to="loc_us-gaap_OperatingIncomeLoss_019ea99f-cc26-76b3-8a5c-fa5a772df69f" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/SegmentandRevenueInformationScheduleofDisaggregationofRevenueDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#SegmentandRevenueInformationScheduleofDisaggregationofRevenueDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/SegmentandRevenueInformationScheduleofDisaggregationofRevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019ea99f-cc27-7ea8-994b-56b70180406f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019ea99f-cc26-7cd3-af6c-e3f587fcc0cd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ea99f-cc27-7ea8-994b-56b70180406f" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019ea99f-cc26-7cd3-af6c-e3f587fcc0cd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019ea99f-cc26-7298-b598-9f0f981fc606" 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_DisaggregationOfRevenueTable_019ea99f-cc26-7cd3-af6c-e3f587fcc0cd" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019ea99f-cc26-7298-b598-9f0f981fc606" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ea99f-cc26-7298-b598-9f0f981fc606_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_019ea99f-cc26-7298-b598-9f0f981fc606" xlink:to="loc_us-gaap_SegmentDomain_019ea99f-cc26-7298-b598-9f0f981fc606_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ea99f-cc26-750d-a52e-9bc7b739cc61" 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_019ea99f-cc26-7298-b598-9f0f981fc606" xlink:to="loc_us-gaap_SegmentDomain_019ea99f-cc26-750d-a52e-9bc7b739cc61" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommercialAirplanesSegmentMember_019ea99f-cc26-7e41-8bea-3c23cadfcff5" xlink:href="ba-20260630.xsd#ba_CommercialAirplanesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cc26-750d-a52e-9bc7b739cc61" xlink:to="loc_ba_CommercialAirplanesSegmentMember_019ea99f-cc26-7e41-8bea-3c23cadfcff5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BoeingDefenseSpaceSecuritySegmentMember_019ea99f-cc26-7870-a0b1-8004bacd3054" xlink:href="ba-20260630.xsd#ba_BoeingDefenseSpaceSecuritySegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cc26-750d-a52e-9bc7b739cc61" xlink:to="loc_ba_BoeingDefenseSpaceSecuritySegmentMember_019ea99f-cc26-7870-a0b1-8004bacd3054" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_GlobalServicesMember_019ea99f-cc26-7bba-b2c1-11eee6d4eef7" xlink:href="ba-20260630.xsd#ba_GlobalServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cc26-750d-a52e-9bc7b739cc61" xlink:to="loc_ba_GlobalServicesMember_019ea99f-cc26-7bba-b2c1-11eee6d4eef7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019ea99f-cc26-708d-9522-381fa3cf980e" 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_DisaggregationOfRevenueTable_019ea99f-cc26-7cd3-af6c-e3f587fcc0cd" xlink:to="loc_srt_ConsolidationItemsAxis_019ea99f-cc26-708d-9522-381fa3cf980e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ea99f-cc26-708d-9522-381fa3cf980e_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_019ea99f-cc26-708d-9522-381fa3cf980e" xlink:to="loc_srt_ConsolidationItemsDomain_019ea99f-cc26-708d-9522-381fa3cf980e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ea99f-cc26-73d7-8534-c30299a5e6c6" 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_019ea99f-cc26-708d-9522-381fa3cf980e" xlink:to="loc_srt_ConsolidationItemsDomain_019ea99f-cc26-73d7-8534-c30299a5e6c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019ea99f-cc26-71e3-ae1c-b6a18ca6797d" 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_019ea99f-cc26-73d7-8534-c30299a5e6c6" xlink:to="loc_us-gaap_OperatingSegmentsMember_019ea99f-cc26-71e3-ae1c-b6a18ca6797d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_019ea99f-cc26-7e73-b57d-94f69554d270" 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_019ea99f-cc26-73d7-8534-c30299a5e6c6" xlink:to="loc_us-gaap_IntersegmentEliminationMember_019ea99f-cc26-7e73-b57d-94f69554d270" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019ea99f-cc26-7ae9-8f62-0df03247c404" 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_DisaggregationOfRevenueTable_019ea99f-cc26-7cd3-af6c-e3f587fcc0cd" xlink:to="loc_srt_StatementGeographicalAxis_019ea99f-cc26-7ae9-8f62-0df03247c404" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019ea99f-cc26-7ae9-8f62-0df03247c404_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_019ea99f-cc26-7ae9-8f62-0df03247c404" xlink:to="loc_srt_SegmentGeographicalDomain_019ea99f-cc26-7ae9-8f62-0df03247c404_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019ea99f-cc26-74ad-aef8-fe3674cba33c" 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_019ea99f-cc26-7ae9-8f62-0df03247c404" xlink:to="loc_srt_SegmentGeographicalDomain_019ea99f-cc26-74ad-aef8-fe3674cba33c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019ea99f-cc26-7f01-8d82-7a0aedc282c4" 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_019ea99f-cc26-74ad-aef8-fe3674cba33c" xlink:to="loc_country_US_019ea99f-cc26-7f01-8d82-7a0aedc282c4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonUsMember_019ea99f-cc26-7ea7-8ad7-73592b89c8f3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019ea99f-cc26-74ad-aef8-fe3674cba33c" xlink:to="loc_us-gaap_NonUsMember_019ea99f-cc26-7ea7-8ad7-73592b89c8f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EuropeMember_019ea99f-cc26-7b9c-a773-3b40adcd7f15" 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_us-gaap_NonUsMember_019ea99f-cc26-7ea7-8ad7-73592b89c8f3" xlink:to="loc_srt_EuropeMember_019ea99f-cc26-7b9c-a773-3b40adcd7f15" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaMember_019ea99f-cc26-7742-b82a-80dc3155ad1e" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_AsiaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonUsMember_019ea99f-cc26-7ea7-8ad7-73592b89c8f3" xlink:to="loc_srt_AsiaMember_019ea99f-cc26-7742-b82a-80dc3155ad1e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MiddleEastMember_019ea99f-cc26-75a2-89dc-1e6b7e05a593" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MiddleEastMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonUsMember_019ea99f-cc26-7ea7-8ad7-73592b89c8f3" xlink:to="loc_us-gaap_MiddleEastMember_019ea99f-cc26-75a2-89dc-1e6b7e05a593" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_OtherMember_019ea99f-cc26-7123-9358-ea2731000406" xlink:href="ba-20260630.xsd#ba_OtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonUsMember_019ea99f-cc26-7ea7-8ad7-73592b89c8f3" xlink:to="loc_ba_OtherMember_019ea99f-cc26-7123-9358-ea2731000406" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_019ea99f-cc26-738a-b22b-f60d36e8b970" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TimingOfTransferOfGoodOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019ea99f-cc26-7cd3-af6c-e3f587fcc0cd" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_019ea99f-cc26-738a-b22b-f60d36e8b970" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_019ea99f-cc26-738a-b22b-f60d36e8b970_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TimingOfTransferOfGoodOrServiceDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_019ea99f-cc26-738a-b22b-f60d36e8b970" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_019ea99f-cc26-738a-b22b-f60d36e8b970_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_019ea99f-cc27-7c7d-bcd8-1b6ed3de72ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TimingOfTransferOfGoodOrServiceDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_019ea99f-cc26-738a-b22b-f60d36e8b970" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_019ea99f-cc27-7c7d-bcd8-1b6ed3de72ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransferredAtPointInTimeMember_019ea99f-cc27-73df-a39c-8ac9148783af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransferredAtPointInTimeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_019ea99f-cc27-7c7d-bcd8-1b6ed3de72ce" xlink:to="loc_us-gaap_TransferredAtPointInTimeMember_019ea99f-cc27-73df-a39c-8ac9148783af" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransferredOverTimeMember_019ea99f-cc27-74f9-bada-d37960d7695f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransferredOverTimeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_019ea99f-cc27-7c7d-bcd8-1b6ed3de72ce" xlink:to="loc_us-gaap_TransferredOverTimeMember_019ea99f-cc27-74f9-bada-d37960d7695f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerBasisOfPricingAxis_019ea99f-cc27-7761-af08-c2cbecbd1ba8" 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_DisaggregationOfRevenueTable_019ea99f-cc26-7cd3-af6c-e3f587fcc0cd" xlink:to="loc_us-gaap_ContractWithCustomerBasisOfPricingAxis_019ea99f-cc27-7761-af08-c2cbecbd1ba8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_019ea99f-cc27-7761-af08-c2cbecbd1ba8_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_019ea99f-cc27-7761-af08-c2cbecbd1ba8" xlink:to="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_019ea99f-cc27-7761-af08-c2cbecbd1ba8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_019ea99f-cc27-7519-b5d0-fa53ebab6a5a" 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_019ea99f-cc27-7761-af08-c2cbecbd1ba8" xlink:to="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_019ea99f-cc27-7519-b5d0-fa53ebab6a5a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FixedPriceContractMember_019ea99f-cc27-7f8d-85dd-a44d0da6bee8" 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_019ea99f-cc27-7519-b5d0-fa53ebab6a5a" xlink:to="loc_us-gaap_FixedPriceContractMember_019ea99f-cc27-7f8d-85dd-a44d0da6bee8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransferredAtPointInTimeMember_019ea99f-cc27-7883-b23e-9fc8fdde6638" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransferredAtPointInTimeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractWithCustomerBasisOfPricingDomain_019ea99f-cc27-7519-b5d0-fa53ebab6a5a" xlink:to="loc_us-gaap_TransferredAtPointInTimeMember_019ea99f-cc27-7883-b23e-9fc8fdde6638" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_019ea99f-cc27-7ad0-ba74-5948f2216b5c" 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_DisaggregationOfRevenueTable_019ea99f-cc26-7cd3-af6c-e3f587fcc0cd" xlink:to="loc_srt_MajorCustomersAxis_019ea99f-cc27-7ad0-ba74-5948f2216b5c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_019ea99f-cc27-7ad0-ba74-5948f2216b5c_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_019ea99f-cc27-7ad0-ba74-5948f2216b5c" xlink:to="loc_srt_NameOfMajorCustomerDomain_019ea99f-cc27-7ad0-ba74-5948f2216b5c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_019ea99f-cc27-7c4d-b36a-b9b803cb6221" 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_019ea99f-cc27-7ad0-ba74-5948f2216b5c" xlink:to="loc_srt_NameOfMajorCustomerDomain_019ea99f-cc27-7c4d-b36a-b9b803cb6221" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommercialCustomersMember_019ea99f-cc27-7864-ba7e-826e8e423085" xlink:href="ba-20260630.xsd#ba_CommercialCustomersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019ea99f-cc27-7c4d-b36a-b9b803cb6221" xlink:to="loc_ba_CommercialCustomersMember_019ea99f-cc27-7864-ba7e-826e8e423085" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_GovernmentCustomersMember_019ea99f-cc27-7c7d-8af2-6a5a88ee1652" xlink:href="ba-20260630.xsd#ba_GovernmentCustomersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019ea99f-cc27-7c4d-b36a-b9b803cb6221" xlink:to="loc_ba_GovernmentCustomersMember_019ea99f-cc27-7c7d-8af2-6a5a88ee1652" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_ExternalCustomersMember_019ea99f-cc27-753a-a3c6-bd23269434fb" xlink:href="ba-20260630.xsd#ba_ExternalCustomersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019ea99f-cc27-7c4d-b36a-b9b803cb6221" xlink:to="loc_ba_ExternalCustomersMember_019ea99f-cc27-753a-a3c6-bd23269434fb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_USGovernmentContractsMember_019ea99f-cc27-7d6c-9e85-beb496baf8ce" xlink:href="ba-20260630.xsd#ba_USGovernmentContractsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_019ea99f-cc27-7c4d-b36a-b9b803cb6221" xlink:to="loc_ba_USGovernmentContractsMember_019ea99f-cc27-7d6c-9e85-beb496baf8ce" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AdjustmentsAxis_019f1f95-33df-7844-95f0-626062506802" xlink:href="ba-20260630.xsd#ba_AdjustmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019ea99f-cc26-7cd3-af6c-e3f587fcc0cd" xlink:to="loc_ba_AdjustmentsAxis_019f1f95-33df-7844-95f0-626062506802" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AdjustmentsDomain_019f1f95-33df-7844-95f0-626062506802_default" xlink:href="ba-20260630.xsd#ba_AdjustmentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_ba_AdjustmentsAxis_019f1f95-33df-7844-95f0-626062506802" xlink:to="loc_ba_AdjustmentsDomain_019f1f95-33df-7844-95f0-626062506802_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_AdjustmentsDomain_019f1f95-33df-7269-9072-efcf7185127c" xlink:href="ba-20260630.xsd#ba_AdjustmentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_ba_AdjustmentsAxis_019f1f95-33df-7844-95f0-626062506802" xlink:to="loc_ba_AdjustmentsDomain_019f1f95-33df-7269-9072-efcf7185127c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CustomerConcessionsMember_019f1f95-33df-7527-ad72-54dda0186cee" xlink:href="ba-20260630.xsd#ba_CustomerConcessionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_AdjustmentsDomain_019f1f95-33df-7269-9072-efcf7185127c" xlink:to="loc_ba_CustomerConcessionsMember_019f1f95-33df-7527-ad72-54dda0186cee" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommercialAircraftProgramsAxis_019f1f95-33df-7b4e-9275-b3b1a9189e23" xlink:href="ba-20260630.xsd#ba_CommercialAircraftProgramsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019ea99f-cc26-7cd3-af6c-e3f587fcc0cd" xlink:to="loc_ba_CommercialAircraftProgramsAxis_019f1f95-33df-7b4e-9275-b3b1a9189e23" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommercialAircraftProgramsDomain_019f1f95-33df-7b4e-9275-b3b1a9189e23_default" xlink:href="ba-20260630.xsd#ba_CommercialAircraftProgramsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_ba_CommercialAircraftProgramsAxis_019f1f95-33df-7b4e-9275-b3b1a9189e23" xlink:to="loc_ba_CommercialAircraftProgramsDomain_019f1f95-33df-7b4e-9275-b3b1a9189e23_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommercialAircraftProgramsDomain_019f1f95-33df-7955-a1f0-60f428513b06" xlink:href="ba-20260630.xsd#ba_CommercialAircraftProgramsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_ba_CommercialAircraftProgramsAxis_019f1f95-33df-7b4e-9275-b3b1a9189e23" xlink:to="loc_ba_CommercialAircraftProgramsDomain_019f1f95-33df-7955-a1f0-60f428513b06" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_B737MaxMember_019f1f95-33df-7dc4-8b08-48353800d7a5" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_B737MaxMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ba_CommercialAircraftProgramsDomain_019f1f95-33df-7955-a1f0-60f428513b06" xlink:to="loc_srt_B737MaxMember_019f1f95-33df-7dc4-8b08-48353800d7a5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019ea99f-cc27-79b0-ac2f-998584c89c80" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ea99f-cc27-7ea8-994b-56b70180406f" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019ea99f-cc27-79b0-ac2f-998584c89c80" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019ea99f-cc27-7fda-ba4d-865857923f7f" 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_DisaggregationOfRevenueLineItems_019ea99f-cc27-7ea8-994b-56b70180406f" xlink:to="loc_us-gaap_Revenues_019ea99f-cc27-7fda-ba4d-865857923f7f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_RevenuefromContractwithCustomerexcludingassessedtaxPercentage_019ea99f-cc27-798b-ad43-f2867c177b51" xlink:href="ba-20260630.xsd#ba_RevenuefromContractwithCustomerexcludingassessedtaxPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019ea99f-cc27-7ea8-994b-56b70180406f" xlink:to="loc_ba_RevenuefromContractwithCustomerexcludingassessedtaxPercentage_019ea99f-cc27-798b-ad43-f2867c177b51" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/SegmentandRevenueInformationScheduleofSegmentReconciliationofOtherItemsfromSegmentstoConsolidatedDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#SegmentandRevenueInformationScheduleofSegmentReconciliationofOtherItemsfromSegmentstoConsolidatedDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/SegmentandRevenueInformationScheduleofSegmentReconciliationofOtherItemsfromSegmentstoConsolidatedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc27-7c39-9445-5505a48c3121" 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_019ea99f-cc27-75e6-a394-fbe4e8835186" 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_019ea99f-cc27-7c39-9445-5505a48c3121" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ea99f-cc27-75e6-a394-fbe4e8835186" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019ea99f-cc27-73a4-ac80-ae490cd90ec5" 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_019ea99f-cc27-75e6-a394-fbe4e8835186" xlink:to="loc_srt_ConsolidationItemsAxis_019ea99f-cc27-73a4-ac80-ae490cd90ec5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-73a4-ac80-ae490cd90ec5_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_019ea99f-cc27-73a4-ac80-ae490cd90ec5" xlink:to="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-73a4-ac80-ae490cd90ec5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-77d5-8531-d3ac5c5bbf07" 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_019ea99f-cc27-73a4-ac80-ae490cd90ec5" xlink:to="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-77d5-8531-d3ac5c5bbf07" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CorporateReconcilingItemsAndEliminationsMember_019ea99f-cc27-7b4c-96df-ca7d94b509ba" xlink:href="ba-20260630.xsd#ba_CorporateReconcilingItemsAndEliminationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-77d5-8531-d3ac5c5bbf07" xlink:to="loc_ba_CorporateReconcilingItemsAndEliminationsMember_019ea99f-cc27-7b4c-96df-ca7d94b509ba" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_019ea99f-cc27-75af-b0a6-6901afc5612f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc27-7c39-9445-5505a48c3121" xlink:to="loc_us-gaap_ShareBasedCompensation_019ea99f-cc27-75af-b0a6-6901afc5612f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredCompensationArrangementWithIndividualCompensationExpense_019ea99f-cc27-7efa-a86c-de6e181435ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredCompensationArrangementWithIndividualCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc27-7c39-9445-5505a48c3121" xlink:to="loc_us-gaap_DeferredCompensationArrangementWithIndividualCompensationExpense_019ea99f-cc27-7efa-a86c-de6e181435ea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestCostsCapitalized_019ea99f-cc27-70e3-9da7-f6b5d6c48e85" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestCostsCapitalized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc27-7c39-9445-5505a48c3121" xlink:to="loc_us-gaap_InterestCostsCapitalized_019ea99f-cc27-70e3-9da7-f6b5d6c48e85" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_019ea99f-cc27-7789-8c76-33238ccd8285" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc27-7c39-9445-5505a48c3121" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_019ea99f-cc27-7789-8c76-33238ccd8285" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_EliminationsAndOtherUnallocatedItems_019ea99f-cc27-747d-ba77-c8147864b5e0" xlink:href="ba-20260630.xsd#ba_EliminationsAndOtherUnallocatedItems"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc27-7c39-9445-5505a48c3121" xlink:to="loc_ba_EliminationsAndOtherUnallocatedItems_019ea99f-cc27-747d-ba77-c8147864b5e0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_OperatingIncomeLossExcludingUnallocatedPensionAndPostretirementAdjustments_019ea99f-cc27-721c-af5f-80dc9ce9c847" xlink:href="ba-20260630.xsd#ba_OperatingIncomeLossExcludingUnallocatedPensionAndPostretirementAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc27-7c39-9445-5505a48c3121" xlink:to="loc_ba_OperatingIncomeLossExcludingUnallocatedPensionAndPostretirementAdjustments_019ea99f-cc27-721c-af5f-80dc9ce9c847" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/SegmentandRevenueInformationComponentsofFinancialAccountingStandardsandCostAccountingStandardsAdjustmentDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#SegmentandRevenueInformationComponentsofFinancialAccountingStandardsandCostAccountingStandardsAdjustmentDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/SegmentandRevenueInformationComponentsofFinancialAccountingStandardsandCostAccountingStandardsAdjustmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc27-7086-b76a-08adce620ccc" 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_019ea99f-cc27-73f1-b03c-7009d5e064b5" 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_019ea99f-cc27-7086-b76a-08adce620ccc" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ea99f-cc27-73f1-b03c-7009d5e064b5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019ea99f-cc27-7048-8b3c-6b7857378f85" 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_019ea99f-cc27-73f1-b03c-7009d5e064b5" xlink:to="loc_srt_ConsolidationItemsAxis_019ea99f-cc27-7048-8b3c-6b7857378f85" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-7048-8b3c-6b7857378f85_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_019ea99f-cc27-7048-8b3c-6b7857378f85" xlink:to="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-7048-8b3c-6b7857378f85_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-7690-9661-1a078bbd7890" 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_019ea99f-cc27-7048-8b3c-6b7857378f85" xlink:to="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-7690-9661-1a078bbd7890" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CorporateReconcilingItemsAndEliminationsMember_019ea99f-cc27-71ea-970e-71e117079c95" xlink:href="ba-20260630.xsd#ba_CorporateReconcilingItemsAndEliminationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-7690-9661-1a078bbd7890" xlink:to="loc_ba_CorporateReconcilingItemsAndEliminationsMember_019ea99f-cc27-71ea-970e-71e117079c95" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_019ea99f-cc27-786b-9d95-afdb13b716ff" 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_ScheduleOfSegmentReportingInformationBySegmentTable_019ea99f-cc27-73f1-b03c-7009d5e064b5" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_019ea99f-cc27-786b-9d95-afdb13b716ff" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_019ea99f-cc27-786b-9d95-afdb13b716ff_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_019ea99f-cc27-786b-9d95-afdb13b716ff" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_019ea99f-cc27-786b-9d95-afdb13b716ff_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_019ea99f-cc27-746b-b933-597152c1b188" 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_019ea99f-cc27-786b-9d95-afdb13b716ff" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_019ea99f-cc27-746b-b933-597152c1b188" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_019ea99f-cc27-73c7-ae3a-10d8282bc44f" 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_019ea99f-cc27-746b-b933-597152c1b188" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_019ea99f-cc27-73c7-ae3a-10d8282bc44f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_019ea99f-cc27-7dd4-bf41-467fd83d3a0f" 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_019ea99f-cc27-746b-b933-597152c1b188" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_019ea99f-cc27-7dd4-bf41-467fd83d3a0f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_FASCASServiceCostAdjustment_019ea99f-cc27-7b7a-8020-d2d34498eccb" xlink:href="ba-20260630.xsd#ba_FASCASServiceCostAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc27-7086-b76a-08adce620ccc" xlink:to="loc_ba_FASCASServiceCostAdjustment_019ea99f-cc27-7b7a-8020-d2d34498eccb" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/SegmentandRevenueInformationReconciliationofAssetsfromSegmenttoConsolidatedDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#SegmentandRevenueInformationReconciliationofAssetsfromSegmenttoConsolidatedDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/SegmentandRevenueInformationReconciliationofAssetsfromSegmenttoConsolidatedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc27-7bfb-8e8a-dc9912096b67" 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_019ea99f-cc27-7ff1-a6be-aa45b612d871" 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_019ea99f-cc27-7bfb-8e8a-dc9912096b67" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ea99f-cc27-7ff1-a6be-aa45b612d871" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019ea99f-cc27-7972-92ce-86eacca4f00a" 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_019ea99f-cc27-7ff1-a6be-aa45b612d871" xlink:to="loc_srt_ConsolidationItemsAxis_019ea99f-cc27-7972-92ce-86eacca4f00a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-7972-92ce-86eacca4f00a_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_019ea99f-cc27-7972-92ce-86eacca4f00a" xlink:to="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-7972-92ce-86eacca4f00a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-7d3f-b719-67de2f979ea0" 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_019ea99f-cc27-7972-92ce-86eacca4f00a" xlink:to="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-7d3f-b719-67de2f979ea0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019ea99f-cc27-739d-9683-b64c95d8d020" 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_019ea99f-cc27-7d3f-b719-67de2f979ea0" xlink:to="loc_us-gaap_OperatingSegmentsMember_019ea99f-cc27-739d-9683-b64c95d8d020" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CorporateReconcilingItemsAndEliminationsMember_019ea99f-cc27-7598-825d-a8497ae3cb96" xlink:href="ba-20260630.xsd#ba_CorporateReconcilingItemsAndEliminationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-7d3f-b719-67de2f979ea0" xlink:to="loc_ba_CorporateReconcilingItemsAndEliminationsMember_019ea99f-cc27-7598-825d-a8497ae3cb96" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019ea99f-cc27-760f-aee0-88f275f11712" 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_019ea99f-cc27-7ff1-a6be-aa45b612d871" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019ea99f-cc27-760f-aee0-88f275f11712" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ea99f-cc27-760f-aee0-88f275f11712_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_019ea99f-cc27-760f-aee0-88f275f11712" xlink:to="loc_us-gaap_SegmentDomain_019ea99f-cc27-760f-aee0-88f275f11712_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ea99f-cc27-7ae0-a96a-150e509f1b17" 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_019ea99f-cc27-760f-aee0-88f275f11712" xlink:to="loc_us-gaap_SegmentDomain_019ea99f-cc27-7ae0-a96a-150e509f1b17" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommercialAirplanesSegmentMember_019ea99f-cc27-7bcd-be2e-f771edf76929" xlink:href="ba-20260630.xsd#ba_CommercialAirplanesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cc27-7ae0-a96a-150e509f1b17" xlink:to="loc_ba_CommercialAirplanesSegmentMember_019ea99f-cc27-7bcd-be2e-f771edf76929" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BoeingDefenseSpaceSecuritySegmentMember_019ea99f-cc27-7229-bf8e-e8d0a557feb7" xlink:href="ba-20260630.xsd#ba_BoeingDefenseSpaceSecuritySegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cc27-7ae0-a96a-150e509f1b17" xlink:to="loc_ba_BoeingDefenseSpaceSecuritySegmentMember_019ea99f-cc27-7229-bf8e-e8d0a557feb7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_GlobalServicesMember_019ea99f-cc27-702e-a141-02ac3ac28d2f" xlink:href="ba-20260630.xsd#ba_GlobalServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cc27-7ae0-a96a-150e509f1b17" xlink:to="loc_ba_GlobalServicesMember_019ea99f-cc27-702e-a141-02ac3ac28d2f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019ea99f-cc27-7d86-b489-fe38e8ebe084" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc27-7bfb-8e8a-dc9912096b67" xlink:to="loc_us-gaap_Assets_019ea99f-cc27-7d86-b489-fe38e8ebe084" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/SegmentandRevenueInformationScheduleofCapitalExpendituresbySegmentDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#SegmentandRevenueInformationScheduleofCapitalExpendituresbySegmentDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/SegmentandRevenueInformationScheduleofCapitalExpendituresbySegmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc27-7289-bc2e-11606669bb53" 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_019ea99f-cc27-782f-b7ca-47c6f72079ee" 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_019ea99f-cc27-7289-bc2e-11606669bb53" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ea99f-cc27-782f-b7ca-47c6f72079ee" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019ea99f-cc27-70da-b2a1-b1cecc91ad35" 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_019ea99f-cc27-782f-b7ca-47c6f72079ee" xlink:to="loc_srt_ConsolidationItemsAxis_019ea99f-cc27-70da-b2a1-b1cecc91ad35" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-70da-b2a1-b1cecc91ad35_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_019ea99f-cc27-70da-b2a1-b1cecc91ad35" xlink:to="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-70da-b2a1-b1cecc91ad35_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-7f74-9ae5-779cfeee8441" 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_019ea99f-cc27-70da-b2a1-b1cecc91ad35" xlink:to="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-7f74-9ae5-779cfeee8441" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019ea99f-cc27-75a3-b9e1-b4ba5e67b6a6" 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_019ea99f-cc27-7f74-9ae5-779cfeee8441" xlink:to="loc_us-gaap_OperatingSegmentsMember_019ea99f-cc27-75a3-b9e1-b4ba5e67b6a6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CorporateReconcilingItemsAndEliminationsMember_019ea99f-cc27-7d08-a666-c6ec4533b4d0" xlink:href="ba-20260630.xsd#ba_CorporateReconcilingItemsAndEliminationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-7f74-9ae5-779cfeee8441" xlink:to="loc_ba_CorporateReconcilingItemsAndEliminationsMember_019ea99f-cc27-7d08-a666-c6ec4533b4d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019ea99f-cc27-739f-a4eb-259b628ecad0" 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_019ea99f-cc27-782f-b7ca-47c6f72079ee" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019ea99f-cc27-739f-a4eb-259b628ecad0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ea99f-cc27-739f-a4eb-259b628ecad0_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_019ea99f-cc27-739f-a4eb-259b628ecad0" xlink:to="loc_us-gaap_SegmentDomain_019ea99f-cc27-739f-a4eb-259b628ecad0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ea99f-cc27-7dc5-aa0c-31dd368a7200" 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_019ea99f-cc27-739f-a4eb-259b628ecad0" xlink:to="loc_us-gaap_SegmentDomain_019ea99f-cc27-7dc5-aa0c-31dd368a7200" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommercialAirplanesSegmentMember_019ea99f-cc27-7db9-90de-4219f931c9a8" xlink:href="ba-20260630.xsd#ba_CommercialAirplanesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cc27-7dc5-aa0c-31dd368a7200" xlink:to="loc_ba_CommercialAirplanesSegmentMember_019ea99f-cc27-7db9-90de-4219f931c9a8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BoeingDefenseSpaceSecuritySegmentMember_019ea99f-cc27-720e-a0f8-35ac4d0666f2" xlink:href="ba-20260630.xsd#ba_BoeingDefenseSpaceSecuritySegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cc27-7dc5-aa0c-31dd368a7200" xlink:to="loc_ba_BoeingDefenseSpaceSecuritySegmentMember_019ea99f-cc27-720e-a0f8-35ac4d0666f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_GlobalServicesMember_019ea99f-cc27-7d48-b66e-a65088c5897b" xlink:href="ba-20260630.xsd#ba_GlobalServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cc27-7dc5-aa0c-31dd368a7200" xlink:to="loc_ba_GlobalServicesMember_019ea99f-cc27-7d48-b66e-a65088c5897b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentExpenditureAdditionToLongLivedAssets_019ea99f-cc27-7fae-a9e3-f53fef88b156" 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_019ea99f-cc27-7289-bc2e-11606669bb53" xlink:to="loc_us-gaap_SegmentExpenditureAdditionToLongLivedAssets_019ea99f-cc27-7fae-a9e3-f53fef88b156" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.boeing.com/role/SegmentandRevenueInformationScheduleofDepreciationandAmortizationExpensebySegmentDetails" xlink:type="simple" xlink:href="ba-20260630.xsd#SegmentandRevenueInformationScheduleofDepreciationandAmortizationExpensebySegmentDetails"/>
  <link:definitionLink xlink:role="http://www.boeing.com/role/SegmentandRevenueInformationScheduleofDepreciationandAmortizationExpensebySegmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc27-78ec-979b-75de6cdd7a6c" 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_019ea99f-cc27-7c88-8c48-2553f4c5502c" 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_019ea99f-cc27-78ec-979b-75de6cdd7a6c" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019ea99f-cc27-7c88-8c48-2553f4c5502c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019ea99f-cc27-7a5f-b7ad-3ccae4a1d6f3" 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_019ea99f-cc27-7c88-8c48-2553f4c5502c" xlink:to="loc_srt_ConsolidationItemsAxis_019ea99f-cc27-7a5f-b7ad-3ccae4a1d6f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-7a5f-b7ad-3ccae4a1d6f3_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_019ea99f-cc27-7a5f-b7ad-3ccae4a1d6f3" xlink:to="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-7a5f-b7ad-3ccae4a1d6f3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-7ead-85ef-e3e4b3d7d1e5" 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_019ea99f-cc27-7a5f-b7ad-3ccae4a1d6f3" xlink:to="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-7ead-85ef-e3e4b3d7d1e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019ea99f-cc27-74dd-81ab-a8c31e70e7d4" 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_019ea99f-cc27-7ead-85ef-e3e4b3d7d1e5" xlink:to="loc_us-gaap_OperatingSegmentsMember_019ea99f-cc27-74dd-81ab-a8c31e70e7d4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CorporateReconcilingItemsAndEliminationsMember_019ea99f-cc27-7dd2-b390-45943a13d97b" xlink:href="ba-20260630.xsd#ba_CorporateReconcilingItemsAndEliminationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_019ea99f-cc27-7ead-85ef-e3e4b3d7d1e5" xlink:to="loc_ba_CorporateReconcilingItemsAndEliminationsMember_019ea99f-cc27-7dd2-b390-45943a13d97b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_019ea99f-cc27-7bcb-8fad-1c106e059c7e" 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_019ea99f-cc27-7ead-85ef-e3e4b3d7d1e5" xlink:to="loc_us-gaap_IntersegmentEliminationMember_019ea99f-cc27-7bcb-8fad-1c106e059c7e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019ea99f-cc27-7973-9143-caec9e415b17" 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_019ea99f-cc27-7c88-8c48-2553f4c5502c" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019ea99f-cc27-7973-9143-caec9e415b17" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ea99f-cc27-7973-9143-caec9e415b17_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_019ea99f-cc27-7973-9143-caec9e415b17" xlink:to="loc_us-gaap_SegmentDomain_019ea99f-cc27-7973-9143-caec9e415b17_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019ea99f-cc27-74ab-86ca-393b6149dc9b" 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_019ea99f-cc27-7973-9143-caec9e415b17" xlink:to="loc_us-gaap_SegmentDomain_019ea99f-cc27-74ab-86ca-393b6149dc9b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_CommercialAirplanesSegmentMember_019ea99f-cc27-7f2b-ace3-2767d0b3bdc9" xlink:href="ba-20260630.xsd#ba_CommercialAirplanesSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cc27-74ab-86ca-393b6149dc9b" xlink:to="loc_ba_CommercialAirplanesSegmentMember_019ea99f-cc27-7f2b-ace3-2767d0b3bdc9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_BoeingDefenseSpaceSecuritySegmentMember_019ea99f-cc27-7a02-a463-2f109cad46e1" xlink:href="ba-20260630.xsd#ba_BoeingDefenseSpaceSecuritySegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cc27-74ab-86ca-393b6149dc9b" xlink:to="loc_ba_BoeingDefenseSpaceSecuritySegmentMember_019ea99f-cc27-7a02-a463-2f109cad46e1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_GlobalServicesMember_019ea99f-cc27-7836-af19-220daafe7252" xlink:href="ba-20260630.xsd#ba_GlobalServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019ea99f-cc27-74ab-86ca-393b6149dc9b" xlink:to="loc_ba_GlobalServicesMember_019ea99f-cc27-7836-af19-220daafe7252" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_019ea99f-cc27-7ef7-8fd9-83b4573447d0" 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_019ea99f-cc27-78ec-979b-75de6cdd7a6c" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_019ea99f-cc27-7ef7-8fd9-83b4573447d0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_ba_DepreciationAndAmortizationExpenseBusinessSegmentAllocation_019ea99f-cc27-71de-b3e4-9c655fe5e9f8" xlink:href="ba-20260630.xsd#ba_DepreciationAndAmortizationExpenseBusinessSegmentAllocation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019ea99f-cc27-78ec-979b-75de6cdd7a6c" xlink:to="loc_ba_DepreciationAndAmortizationExpenseBusinessSegmentAllocation_019ea99f-cc27-71de-b3e4-9c655fe5e9f8" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://fasb.org/srt/role/srt-eedm/ExtensibleEnumerationLists" xlink:type="simple" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-roles-2026.xsd#eedm1"/>
  <link:definitionLink xlink:role="http://fasb.org/srt/role/srt-eedm/ExtensibleEnumerationLists" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssetsCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract" xlink:to="loc_us-gaap_OtherAssetsCurrent" xlink:type="arc" order="101"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent" xlink:type="arc" order="31"/>
  </link:definitionLink>
</link:linkbase>
