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    <filerInfo>
      <filer>
        <filerCredentials>
          <cik>0001799975</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



    </filerInfo>
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  <formData>
    <issuerInfo>
      <issuerCik>0000350894</issuerCik>
      <issuerName>SEI INVESTMENTS CO</issuerName>
      <secFileNumber>000-10200</secFileNumber>
      <issuerAddress>
        <com:street1>1 FREEDOM VALLEY DRIVE</com:street1>
        <com:city>OAKS</com:city>
        <com:stateOrCountry>PA</com:stateOrCountry>
        <com:zipCode>19456-1100</com:zipCode>
      </issuerAddress>
      <issuerContactPhone>6106761000</issuerContactPhone>
      <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Hicke Ryan</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
      <relationshipsToIssuer>
        <relationshipToIssuer>Officer</relationshipToIssuer>
      </relationshipsToIssuer>
    </issuerInfo>
    <securitiesInformation>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <brokerOrMarketmakerDetails>
        <name>Charles Schwab &amp; Co., Inc.</name>
        <address>
          <com:street1>3000 Schwab Way</com:street1>
          <com:city>Westlake</com:city>
          <com:stateOrCountry>TX</com:stateOrCountry>
          <com:zipCode>76262</com:zipCode>
        </address>
      </brokerOrMarketmakerDetails>
      <noOfUnitsSold>10000</noOfUnitsSold>
      <aggregateMarketValue>749002.00</aggregateMarketValue>
      <noOfUnitsOutstanding>128908648</noOfUnitsOutstanding>
      <approxSaleDate>10/25/2024</approxSaleDate>
      <securitiesExchangeName>NASDAQ</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>10/25/2024</acquiredDate>
      <natureOfAcquisitionTransaction>Employee Stock Option Exercise</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>SEI INVESTMENTS CO</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>10000</amountOfSecuritiesAcquired>
      <paymentDate>10/25/2024</paymentDate>
      <natureOfPayment>Broker Payment for Cashless Exercise</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <noticeSignature>
      <noticeDate>10/25/2024</noticeDate>
      <signature>Ryan Hicke</signature>
    </noticeSignature>
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144
0001799975
XXXXXXXX
LIVE
0000350894
SEI INVESTMENTS CO
000-10200
1 FREEDOM VALLEY DRIVE
OAKS
PA
19456-1100
6106761000
Hicke Ryan
Officer
Common
Charles Schwab & Co., Inc.
3000 Schwab Way
Westlake
TX
76262
10000
749002.00
128908648
10/25/2024
NASDAQ
Common
10/25/2024
Employee Stock Option Exercise
SEI INVESTMENTS CO
N
10000
10/25/2024
Broker Payment for Cashless Exercise
Y
10/25/2024
Ryan Hicke