content: <?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
    <headerData>
      <submissionType>144</submissionType>
      <filerInfo>
        <filer>
          <filerCredentials>
            <cik>0001944544</cik>
            <ccc>XXXXXXXX</ccc>
          </filerCredentials>
        </filer>
        <liveTestFlag>LIVE</liveTestFlag>
  
  
      </filerInfo>
    </headerData>
    <formData>
      <issuerInfo>
        <issuerCik>0001877939</issuerCik>
        <issuerName>Castellum, Inc.</issuerName>
        <secFileNumber>001-41526</secFileNumber>
        <issuerAddress>
          <com:street1>1934 OLD GALLOWS ROAD</com:street1>
          <com:street2>SUITE 350</com:street2>
          <com:city>VIENNA</com:city>
          <com:stateOrCountry>VA</com:stateOrCountry>
          <com:zipCode>22182</com:zipCode>
        </issuerAddress>
        <issuerContactPhone>(703) 752-6157</issuerContactPhone>
        <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Fuller Mark C</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
        <relationshipsToIssuer>
          <relationshipToIssuer>Director</relationshipToIssuer>
          <relationshipToIssuer>10% Stockholder</relationshipToIssuer>
        </relationshipsToIssuer>
      </issuerInfo>
      <securitiesInformation>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <brokerOrMarketmakerDetails>
          <name>First Georgetown Securities, Inc</name>
          <address>
            <com:street1>Diagonal Road, Suite 200,</com:street1>
            <com:city>Alexandria</com:city>
            <com:stateOrCountry>VA</com:stateOrCountry>
            <com:zipCode>22314</com:zipCode>
          </address>
        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>500000</noOfUnitsSold>
        <aggregateMarketValue>490500.00</aggregateMarketValue>
        <noOfUnitsOutstanding>56109928</noOfUnitsOutstanding>
        <approxSaleDate>03/05/2025</approxSaleDate>
        <securitiesExchangeName>NYSE</securitiesExchangeName>
      </securitiesInformation>
      <securitiesToBeSold>
        <securitiesClassTitle>Common</securitiesClassTitle>
        <acquiredDate>07/22/2019</acquiredDate>
        <natureOfAcquisitionTransaction>Private Placement</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Catellum,Inc</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>500000</amountOfSecuritiesAcquired>
        <paymentDate>07/22/2019</paymentDate>
        <natureOfPayment>n/a</natureOfPayment>
      </securitiesToBeSold>
      <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
      <noticeSignature>
        <noticeDate>03/04/2025</noticeDate>
        <signature>/s/ Carmen Zamores as a duly authorized representative of National Financial Services LLC, as attorney-in-fact for Fuller Mark C</signature>
      </noticeSignature>
    </formData>
  </edgarSubmission>
metadata_documents: [{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 2943}]
text: 144
  0001944544
  XXXXXXXX
  LIVE
  0001877939
  Castellum, Inc.
  001-41526
  1934 OLD GALLOWS ROAD
  SUITE 350
  VIENNA
  VA
  22182
  (703) 752-6157
  Fuller Mark C
  Director
  10% Stockholder
  Common
  First Georgetown Securities, Inc
  Diagonal Road, Suite 200,
  Alexandria
  VA
  22314
  500000
  490500.00
  56109928
  03/05/2025
  NYSE
  Common
  07/22/2019
  Private Placement
  Catellum,Inc
  N
  500000
  07/22/2019
  n/a
  Y
  03/04/2025
  /s/ Carmen Zamores as a duly authorized representative of National Financial Services LLC, as attorney-in-fact for Fuller Mark C