    <SEC-DOCUMENT>0000350894-21-000026-index.html : 20210427
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    <ACCEPTANCE-DATETIME>20210427144644
    ACCESSION NUMBER:		0000350894-21-000026
    CONFORMED SUBMISSION TYPE:	DEF 14A
    PUBLIC DOCUMENT COUNT:		49
    CONFORMED PERIOD OF REPORT:	20210602
    FILED AS OF DATE:		20210427
    DATE AS OF CHANGE:		20210427

    FILER:

    	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:		DEF 14A
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	000-10200
    		FILM NUMBER:		21858325

    	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>DEF 14A
    <SEQUENCE>1
    <FILENAME>seicproxyjune22021shareh.htm
    <DESCRIPTION>DEFINITIVE PROXY STATEMENT
    <TEXT>
    Document 1 - file: seicproxyjune22021shareh.htm

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    <SEQUENCE>2
    <FILENAME>seicproxyjune22021shareh001.jpg
    <DESCRIPTION>GRAPHIC
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    Document 2 - file: seicproxyjune22021shareh001.jpg

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    <FILENAME>seicproxyjune22021shareh002.jpg
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    Document 3 - file: seicproxyjune22021shareh002.jpg

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    <FILENAME>seicproxyjune22021shareh003.jpg
    <DESCRIPTION>GRAPHIC
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    Document 4 - file: seicproxyjune22021shareh003.jpg

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    <FILENAME>seicproxyjune22021shareh004.jpg
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    Document 5 - file: seicproxyjune22021shareh004.jpg

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    <FILENAME>seicproxyjune22021shareh005.jpg
    <DESCRIPTION>GRAPHIC
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    Document 6 - file: seicproxyjune22021shareh005.jpg

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    <FILENAME>seicproxyjune22021shareh006.jpg
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    Document 7 - file: seicproxyjune22021shareh006.jpg

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    <FILENAME>seicproxyjune22021shareh007.jpg
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    Document 8 - file: seicproxyjune22021shareh007.jpg

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    <FILENAME>seicproxyjune22021shareh008.jpg
    <DESCRIPTION>GRAPHIC
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    Document 9 - file: seicproxyjune22021shareh008.jpg

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    <FILENAME>seicproxyjune22021shareh009.jpg
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    Document 10 - file: seicproxyjune22021shareh009.jpg

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    <FILENAME>seicproxyjune22021shareh010.jpg
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    Document 11 - file: seicproxyjune22021shareh010.jpg

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    <FILENAME>seicproxyjune22021shareh011.jpg
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    Document 12 - file: seicproxyjune22021shareh011.jpg

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    <FILENAME>seicproxyjune22021shareh012.jpg
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    Document 13 - file: seicproxyjune22021shareh012.jpg

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    <FILENAME>seicproxyjune22021shareh013.jpg
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    Document 14 - file: seicproxyjune22021shareh013.jpg

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    <FILENAME>seicproxyjune22021shareh014.jpg
    <DESCRIPTION>GRAPHIC
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    Document 15 - file: seicproxyjune22021shareh014.jpg

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    <FILENAME>seicproxyjune22021shareh015.jpg
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    Document 16 - file: seicproxyjune22021shareh015.jpg

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    <FILENAME>seicproxyjune22021shareh016.jpg
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    Document 17 - file: seicproxyjune22021shareh016.jpg

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    <FILENAME>seicproxyjune22021shareh017.jpg
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    Document 18 - file: seicproxyjune22021shareh017.jpg

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    <FILENAME>seicproxyjune22021shareh018.jpg
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    Document 19 - file: seicproxyjune22021shareh018.jpg

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    <FILENAME>seicproxyjune22021shareh019.jpg
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    Document 20 - file: seicproxyjune22021shareh019.jpg

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    <FILENAME>seicproxyjune22021shareh020.jpg
    <DESCRIPTION>GRAPHIC
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    Document 21 - file: seicproxyjune22021shareh020.jpg

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    <FILENAME>seicproxyjune22021shareh021.jpg
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    Document 22 - file: seicproxyjune22021shareh021.jpg

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    <SEQUENCE>23
    <FILENAME>seicproxyjune22021shareh022.jpg
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    Document 23 - file: seicproxyjune22021shareh022.jpg

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    <DOCUMENT>
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    <SEQUENCE>24
    <FILENAME>seicproxyjune22021shareh023.jpg
    <DESCRIPTION>GRAPHIC
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    Document 24 - file: seicproxyjune22021shareh023.jpg

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    <DOCUMENT>
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    <SEQUENCE>25
    <FILENAME>seicproxyjune22021shareh024.jpg
    <DESCRIPTION>GRAPHIC
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    Document 25 - file: seicproxyjune22021shareh024.jpg

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    <SEQUENCE>26
    <FILENAME>seicproxyjune22021shareh025.jpg
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    Document 26 - file: seicproxyjune22021shareh025.jpg

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    <FILENAME>seicproxyjune22021shareh026.jpg
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    Document 27 - file: seicproxyjune22021shareh026.jpg

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    <DOCUMENT>
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    <SEQUENCE>28
    <FILENAME>seicproxyjune22021shareh027.jpg
    <DESCRIPTION>GRAPHIC
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    Document 28 - file: seicproxyjune22021shareh027.jpg

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    <SEQUENCE>29
    <FILENAME>seicproxyjune22021shareh028.jpg
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    Document 29 - file: seicproxyjune22021shareh028.jpg

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    <DOCUMENT>
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    <SEQUENCE>30
    <FILENAME>seicproxyjune22021shareh029.jpg
    <DESCRIPTION>GRAPHIC
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    Document 30 - file: seicproxyjune22021shareh029.jpg

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    <SEQUENCE>31
    <FILENAME>seicproxyjune22021shareh030.jpg
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    Document 31 - file: seicproxyjune22021shareh030.jpg

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    <SEQUENCE>32
    <FILENAME>seicproxyjune22021shareh031.jpg
    <DESCRIPTION>GRAPHIC
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    Document 32 - file: seicproxyjune22021shareh031.jpg

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    <SEQUENCE>33
    <FILENAME>seicproxyjune22021shareh032.jpg
    <DESCRIPTION>GRAPHIC
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    Document 33 - file: seicproxyjune22021shareh032.jpg

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    <SEQUENCE>34
    <FILENAME>seicproxyjune22021shareh033.jpg
    <DESCRIPTION>GRAPHIC
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    Document 34 - file: seicproxyjune22021shareh033.jpg

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    <SEQUENCE>35
    <FILENAME>seicproxyjune22021shareh034.jpg
    <DESCRIPTION>GRAPHIC
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    Document 35 - file: seicproxyjune22021shareh034.jpg

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    <SEQUENCE>36
    <FILENAME>seicproxyjune22021shareh035.jpg
    <DESCRIPTION>GRAPHIC
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    Document 36 - file: seicproxyjune22021shareh035.jpg

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    <SEQUENCE>37
    <FILENAME>seicproxyjune22021shareh036.jpg
    <DESCRIPTION>GRAPHIC
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    Document 37 - file: seicproxyjune22021shareh036.jpg

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    <SEQUENCE>38
    <FILENAME>seicproxyjune22021shareh037.jpg
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    Document 38 - file: seicproxyjune22021shareh037.jpg

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    <FILENAME>seicproxyjune22021shareh038.jpg
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    <FILENAME>seicproxyjune22021shareh039.jpg
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    Document 40 - file: seicproxyjune22021shareh039.jpg

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    Document 41 - file: seicproxyjune22021shareh040.jpg

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    <FILENAME>seicproxyjune22021shareh041.jpg
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    Document 42 - file: seicproxyjune22021shareh041.jpg

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    <SEQUENCE>43
    <FILENAME>seicproxyjune22021shareh042.jpg
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    Document 43 - file: seicproxyjune22021shareh042.jpg

    </DOCUMENT>
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    <FILENAME>seicproxyjune22021shareh043.jpg
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    Document 44 - file: seicproxyjune22021shareh043.jpg

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    <FILENAME>seicproxyjune22021shareh044.jpg
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    <SEQUENCE>47
    <FILENAME>seicproxyjune22021shareh046.jpg
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    <SEQUENCE>48
    <FILENAME>seicproxyjune22021shareh047.jpg
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    </DOCUMENT>
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    <TYPE>GRAPHIC
    <SEQUENCE>49
    <FILENAME>seicproxyjune22021shareh048.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 49 - file: seicproxyjune22021shareh048.jpg

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