<SEC-DOCUMENT>0000350894-18-000033.txt : 20180514
<SEC-HEADER>0000350894-18-000033.hdr.sgml : 20180514
<ACCEPTANCE-DATETIME>20180514110849
ACCESSION NUMBER:		0000350894-18-000033
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180514
FILED AS OF DATE:		20180514
DATE AS OF CHANGE:		20180514

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Klauder N Jeffrey
		CENTRAL INDEX KEY:			0001187548

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-10200
		FILM NUMBER:		18829227

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

	FORMER NAME:	
		FORMER CONFORMED NAME:	KLAUDER N JEFFREY
		DATE OF NAME CHANGE:	20020909

ISSUER:		

	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

	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
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-05-14</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0000350894</issuerCik>
        <issuerName>SEI INVESTMENTS CO</issuerName>
        <issuerTradingSymbol>SEIC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001187548</rptOwnerCik>
            <rptOwnerName>Klauder N Jeffrey</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE FREEDOM VALLEY DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>OAKS</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>19456</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EXECUTIVE VICE PRESIDENT</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>COMMON STOCK</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>42194</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <remarks>Filed solely to report change in status as reporting person.  No purchase or sale transaction reported.</remarks>

    <ownerSignature>
        <signatureName>RUTH MONTGOMERY (ATTORNEY IN FACT)</signatureName>
        <signatureDate>2018-05-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
