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      <submissionType>144</submissionType>
      <filerInfo>
        <filer>
          <filerCredentials>
            <!-- Field: Pseudo-Tag; ID: Name; Data: Aditya Mahesh -->
            <cik>0001706941</cik>
            <ccc>XXXXXXXX</ccc>
          </filerCredentials>
        </filer>
        <liveTestFlag>LIVE</liveTestFlag>
  
  
  
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      <issuerInfo>
        <issuerCik>0000891478</issuerCik>
        <issuerName>BANCO SANTANDER SA</issuerName>
        <secFileNumber>001-12518</secFileNumber>
        <issuerAddress>
          <com:street1>Ciudad Grupo Santander</com:street1>
          <com:street2>28660 Boadilla del Monte</com:street2>
          <com:city>Madrid</com:city>
          <com:stateOrCountry>U3</com:stateOrCountry>
          <com:zipCode>28660</com:zipCode>
        </issuerAddress>
        <issuerContactPhone>34-91-259-6520</issuerContactPhone>
        <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Mahesh Chatta Aditya</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
        <relationshipsToIssuer>
          <relationshipToIssuer>Chief Risk Officer</relationshipToIssuer>
        </relationshipsToIssuer>
      </issuerInfo>
      <securitiesInformation>
        <securitiesClassTitle>American Depositary Shares, each representing the right to receive one Share of Capital Stock of Banco Santander, S.A., par value euro 0.50 each</securitiesClassTitle>
        <brokerOrMarketmakerDetails>
          <name>Timothy J Hanson</name>
          <address>
            <com:street1>JP Morgan Securities</com:street1>
            <com:street2>925 Westchester Avenue, Suite 302</com:street2>
            <com:city>West Harrison</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10604</com:zipCode>
          </address>
        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>10665</noOfUnitsSold>
        <aggregateMarketValue>50658.75</aggregateMarketValue>
        <noOfUnitsOutstanding>16184146059</noOfUnitsOutstanding>
        <approxSaleDate>11/08/2024</approxSaleDate>
        <securitiesExchangeName>NYSE</securitiesExchangeName>
      </securitiesInformation>
      <securitiesToBeSold>
        <securitiesClassTitle>American Depositary Shares, each representing the right to receive one Share of Capital Stock of Banco Santander, S.A., par value euro 0.50 each</securitiesClassTitle>
        <acquiredDate>11/06/2024</acquiredDate>
        <natureOfAcquisitionTransaction>Open market purchase</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Open market purchase</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>10665</amountOfSecuritiesAcquired>
        <paymentDate>11/06/2024</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
      </securitiesToBeSold>
      <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
      <noticeSignature>
        <noticeDate>11/11/2024</noticeDate>
        <signature>/s/ Mahesh Chatta Aditya</signature>
      </noticeSignature>
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text: 144
  0001706941
  XXXXXXXX
  LIVE
  0000891478
  BANCO SANTANDER SA
  001-12518
  Ciudad Grupo Santander
  28660 Boadilla del Monte
  Madrid
  U3
  28660
  34-91-259-6520
  Mahesh Chatta Aditya
  Chief Risk Officer
  American Depositary Shares, each representing the right to receive one Share of Capital Stock of Banco Santander, S.A., par value euro 0.50 each
  Timothy J Hanson
  JP Morgan Securities
  925 Westchester Avenue, Suite 302
  West Harrison
  NY
  10604
  10665
  50658.75
  16184146059
  11/08/2024
  NYSE
  American Depositary Shares, each representing the right to receive one Share of Capital Stock of Banco Santander, S.A., par value euro 0.50 each
  11/06/2024
  Open market purchase
  Open market purchase
  N
  10665
  11/06/2024
  Cash
  Y
  11/11/2024
  /s/ Mahesh Chatta Aditya