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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:01a151d9-8039-70f7-80d4-d01bd1f2d2b4,g:f929a59d-97ef-40bf-ae2d-8cf29cd81898-->
<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.centrusenergy.com/role/Cover" xlink:type="simple" xlink:href="leu-20261016.xsd#Cover"/>
  <link:definitionLink xlink:role="http://www.centrusenergy.com/role/Cover" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationTable_01a151d9-8039-736e-83de-c0a5866c1992" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_DocumentInformationTable_01a151d9-8039-736e-83de-c0a5866c1992" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationDocumentAxis_01a151d9-8039-76be-955e-67467d3081ec" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationDocumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_01a151d9-8039-736e-83de-c0a5866c1992" xlink:to="loc_dei_DocumentInformationDocumentAxis_01a151d9-8039-76be-955e-67467d3081ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentDomain_01a151d9-8039-76be-955e-67467d3081ec_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_DocumentInformationDocumentAxis_01a151d9-8039-76be-955e-67467d3081ec" xlink:to="loc_dei_DocumentDomain_01a151d9-8039-76be-955e-67467d3081ec_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentDomain_01a151d9-8039-722b-bb33-d02dcba6a932" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_DocumentInformationDocumentAxis_01a151d9-8039-76be-955e-67467d3081ec" xlink:to="loc_dei_DocumentDomain_01a151d9-8039-722b-bb33-d02dcba6a932" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_01a151d9-8039-7bf5-b643-58a14a8fbb67" 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_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_EntityCentralIndexKey_01a151d9-8039-7bf5-b643-58a14a8fbb67" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_01a151d9-8039-7fba-afaa-1d8e6e756b37" 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_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_AmendmentFlag_01a151d9-8039-7fba-afaa-1d8e6e756b37" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_01a151d9-8039-78c2-aed5-cb3af0a60904" 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_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_EntityRegistrantName_01a151d9-8039-78c2-aed5-cb3af0a60904" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_01a151d9-8039-7b89-a309-e489edec2206" 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_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_DocumentPeriodEndDate_01a151d9-8039-7b89-a309-e489edec2206" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_01a151d9-8039-76c5-8968-2f3779d7a70c" 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_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_DocumentType_01a151d9-8039-76c5-8968-2f3779d7a70c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_01a151d9-8039-71ba-8432-5c10e502b19e" 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_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_EntityAddressAddressLine1_01a151d9-8039-71ba-8432-5c10e502b19e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine2_01a151d9-8039-793e-adbe-4ba1a01d5a37" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_EntityAddressAddressLine2_01a151d9-8039-793e-adbe-4ba1a01d5a37" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_01a151d9-8039-7196-b349-7016507f6bd0" 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_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_EntityAddressCityOrTown_01a151d9-8039-7196-b349-7016507f6bd0" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_01a151d9-8039-7c17-8973-48bd78c20ff8" 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_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_EntityAddressStateOrProvince_01a151d9-8039-7c17-8973-48bd78c20ff8" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_01a151d9-8039-7cf8-a61c-78534d9ce5d0" 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_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_EntityAddressPostalZipCode_01a151d9-8039-7cf8-a61c-78534d9ce5d0" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_01a151d9-8039-7a78-a9e4-70fc18203ea4" 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_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_CityAreaCode_01a151d9-8039-7a78-a9e4-70fc18203ea4" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_01a151d9-8039-77bc-8578-8703efa8a907" 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_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_LocalPhoneNumber_01a151d9-8039-77bc-8578-8703efa8a907" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_01a151d9-8039-7456-aac3-8a2fdb309e65" 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_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_EntityEmergingGrowthCompany_01a151d9-8039-7456-aac3-8a2fdb309e65" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_01a151d9-8039-77b5-b882-7f2bd5e868ad" 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_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_EntityFileNumber_01a151d9-8039-77b5-b882-7f2bd5e868ad" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_01a151d9-8039-792a-bf9c-48892e6e3693" 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_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_EntityIncorporationStateCountryCode_01a151d9-8039-792a-bf9c-48892e6e3693" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_01a151d9-8039-7380-a43a-7dc8609906f4" 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_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_EntityTaxIdentificationNumber_01a151d9-8039-7380-a43a-7dc8609906f4" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_WrittenCommunications_01a151d9-8039-7137-9359-95a854b7433d" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_WrittenCommunications"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_WrittenCommunications_01a151d9-8039-7137-9359-95a854b7433d" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SolicitingMaterial_01a151d9-8039-7a92-a9d1-85a9250a57bf" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_SolicitingMaterial"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_SolicitingMaterial_01a151d9-8039-7a92-a9d1-85a9250a57bf" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementTenderOffer_01a151d9-8039-7721-ac01-5a109ec5d665" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_PreCommencementTenderOffer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_PreCommencementTenderOffer_01a151d9-8039-7721-ac01-5a109ec5d665" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementIssuerTenderOffer_01a151d9-8039-7eab-adb2-55533c000d95" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_PreCommencementIssuerTenderOffer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_PreCommencementIssuerTenderOffer_01a151d9-8039-7eab-adb2-55533c000d95" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_01a151d9-8039-75fa-8ad8-e63ab5e0448a" 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_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_Security12bTitle_01a151d9-8039-75fa-8ad8-e63ab5e0448a" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_01a151d9-8039-7c73-97ae-35055468ae69" 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_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_TradingSymbol_01a151d9-8039-7c73-97ae-35055468ae69" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_01a151d9-8039-783b-8b35-ca1e62e57395" 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_DocumentInformationLineItems_01a151d9-8039-7a62-a466-6560625237b3" xlink:to="loc_dei_SecurityExchangeName_01a151d9-8039-783b-8b35-ca1e62e57395" xlink:type="arc" order="22"/>
  </link:definitionLink>
</link:linkbase>
