<SEC-DOCUMENT>0001968582-23-000498.txt : 20230911
<SEC-HEADER>0001968582-23-000498.hdr.sgml : 20230911
<ACCEPTANCE-DATETIME>20230911174423
ACCESSION NUMBER:		0001968582-23-000498
CONFORMED SUBMISSION TYPE:	144
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20230911
DATE AS OF CHANGE:		20230911

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SEI INVESTMENTS CO
		CENTRAL INDEX KEY:			0000350894
		STANDARD INDUSTRIAL CLASSIFICATION:	SECURITY BROKERS, DEALERS & FLOTATION COMPANIES [6211]
		IRS NUMBER:				231707341
		STATE OF INCORPORATION:			PA
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		144
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	000-10200
		FILM NUMBER:		231248586

	BUSINESS ADDRESS:	
		STREET 1:		1 FREEDOM VALLEY DRIVE
		CITY:			OAKS
		STATE:			PA
		ZIP:			19456-1100
		BUSINESS PHONE:		6106761000

	MAIL ADDRESS:	
		STREET 1:		1 FREEDOM VALLEY DRIVE
		CITY:			OAKS
		STATE:			PA
		ZIP:			19456-1100

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SEI INVESTMENT CO
		DATE OF NAME CHANGE:	20040806

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SEI CORP
		DATE OF NAME CHANGE:	19920703

REPORTING-OWNER:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			WEST ALFRED P JR
		CENTRAL INDEX KEY:			0001059374

	FILING VALUES:
		FORM TYPE:		144

	MAIL ADDRESS:	
		STREET 1:		1 FREEDOM VALLEY DRIVE
		CITY:			OAKS
		STATE:			PA
		ZIP:			19456
</SEC-HEADER>
<DOCUMENT>
<TYPE>144
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
<XML>
<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
  <!-- Generated by Workiva -->
  <headerData>
    <submissionType>144</submissionType>
    <filerInfo>
      <filer>
        <filerCredentials>
          <cik>0001059374</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



    </filerInfo>
  </headerData>
  <formData>
    <issuerInfo>
      <issuerCik>0000350894</issuerCik>
      <issuerName>SEI Investments Co</issuerName>
      <secFileNumber>000-10200</secFileNumber>
      <issuerAddress>
        <com:street1>One Freedom Valley Drive</com:street1>
        <com:city>Oaks</com:city>
        <com:stateOrCountry>PA</com:stateOrCountry>
        <com:zipCode>19456-100</com:zipCode>
      </issuerAddress>
      <issuerContactPhone>610-676-1000</issuerContactPhone>
      <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Alfred Paul West Jr</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
      <relationshipsToIssuer>
        <relationshipToIssuer>Affiliate</relationshipToIssuer>
      </relationshipsToIssuer>
    </issuerInfo>
    <securitiesInformation>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <brokerOrMarketmakerDetails>
        <name>J.P. Morgan Securities LLC</name>
        <address>
          <com:street1>390 Madison Avenue</com:street1>
          <com:street2>6th Floor</com:street2>
          <com:city>New York</com:city>
          <com:stateOrCountry>NY</com:stateOrCountry>
          <com:zipCode>10017</com:zipCode>
        </address>
      </brokerOrMarketmakerDetails>
      <noOfUnitsSold>213000</noOfUnitsSold>
      <aggregateMarketValue>13020690</aggregateMarketValue>
      <noOfUnitsOutstanding>132358055</noOfUnitsOutstanding>
      <approxSaleDate>09/11/2023</approxSaleDate>
      <securitiesExchangeName>Nasdaq</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>12/03/2018</acquiredDate>
      <natureOfAcquisitionTransaction>Option Exercise</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>15000</amountOfSecuritiesAcquired>
      <paymentDate>12/03/2018</paymentDate>
      <natureOfPayment>n/a</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>11/01/2019</acquiredDate>
      <natureOfAcquisitionTransaction>Private transaction</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>300948</amountOfSecuritiesAcquired>
      <paymentDate>11/01/2019</paymentDate>
      <natureOfPayment>n/a</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>Alfred P West Jr</name>
        <address>
          <com:street1>Care of SEI Investments Co</com:street1>
          <com:street2>1 Freedom Valley Drive</com:street2>
          <com:city>Oaks</com:city>
          <com:stateOrCountry>PA</com:stateOrCountry>
          <com:zipCode>19456-1100</com:zipCode>
        </address>
      </sellerDetails>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <saleDate>06/20/2023</saleDate>
      <amountOfSecuritiesSold>46647</amountOfSecuritiesSold>
      <grossProceeds>2751715</grossProceeds>
    </securitiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>Alfred P West Jr</name>
        <address>
          <com:street1>Care of SEI Investments Co</com:street1>
          <com:street2>1 Freedom Valley Drive</com:street2>
          <com:city>Oaks</com:city>
          <com:stateOrCountry>PA</com:stateOrCountry>
          <com:zipCode>19456-1100</com:zipCode>
        </address>
      </sellerDetails>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <saleDate>06/21/2023</saleDate>
      <amountOfSecuritiesSold>58687</amountOfSecuritiesSold>
      <grossProceeds>3443901</grossProceeds>
    </securitiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>Alfred P West Jr</name>
        <address>
          <com:street1>Care of SEI Investments Co</com:street1>
          <com:street2>1 Freedom Valley Drive</com:street2>
          <com:city>Oaks</com:city>
          <com:stateOrCountry>PA</com:stateOrCountry>
          <com:zipCode>19456-1100</com:zipCode>
        </address>
      </sellerDetails>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <saleDate>06/22/2023</saleDate>
      <amountOfSecuritiesSold>41304</amountOfSecuritiesSold>
      <grossProceeds>2382332</grossProceeds>
    </securitiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>Alfred P West Jr</name>
        <address>
          <com:street1>Care of SEI Investments Co</com:street1>
          <com:street2>1 Freedom Valley Drive</com:street2>
          <com:city>Oaks</com:city>
          <com:stateOrCountry>PA</com:stateOrCountry>
          <com:zipCode>19456-1100</com:zipCode>
        </address>
      </sellerDetails>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <saleDate>06/23/2023</saleDate>
      <amountOfSecuritiesSold>60270</amountOfSecuritiesSold>
      <grossProceeds>3432753</grossProceeds>
    </securitiesSoldInPast3Months>
    <noticeSignature>
      <noticeDate>09/11/2023</noticeDate>
      <signature>J.P. Morgan Securities LLC as agent and attorney-in-fact for Alfred P West Jr</signature>
    </noticeSignature>
  </formData>
</edgarSubmission>
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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
