<SEC-DOCUMENT>0000950103-21-003858.txt : 20210311
<SEC-HEADER>0000950103-21-003858.hdr.sgml : 20210311
<ACCEPTANCE-DATETIME>20210311161805
ACCESSION NUMBER:		0000950103-21-003858
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210301
FILED AS OF DATE:		20210311
DATE AS OF CHANGE:		20210311

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MORGAN STANLEY
		CENTRAL INDEX KEY:			0000895421
		STANDARD INDUSTRIAL CLASSIFICATION:	SECURITY BROKERS, DEALERS & FLOTATION COMPANIES [6211]
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	811-09013
		FILM NUMBER:		21733529

	BUSINESS ADDRESS:	
		STREET 1:		1585 BROADWAY
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036
		BUSINESS PHONE:		212-761-4000

	MAIL ADDRESS:	
		STREET 1:		1585 BROADWAY
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036

	FORMER NAME:	
		FORMER CONFORMED NAME:	MORGAN STANLEY DEAN WITTER & CO
		DATE OF NAME CHANGE:	19980326

	FORMER NAME:	
		FORMER CONFORMED NAME:	DEAN WITTER DISCOVER & CO
		DATE OF NAME CHANGE:	19960315

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			EATON VANCE SENIOR INCOME TRUST
		CENTRAL INDEX KEY:			0001070732
		IRS NUMBER:				043435040

	BUSINESS ADDRESS:	
		STREET 1:		TWO INTERNATIONAL PLACE
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02110
		BUSINESS PHONE:		617-482-8260

	MAIL ADDRESS:	
		STREET 1:		TWO INTERNATIONAL PLACE
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02110
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>dp147607_3-evf.xml
<DESCRIPTION>FORM 3
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2021-03-01</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001070732</issuerCik>
        <issuerName>EATON VANCE SENIOR INCOME TRUST</issuerName>
        <issuerTradingSymbol>EVF</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000895421</rptOwnerCik>
            <rptOwnerName>MORGAN STANLEY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1585 BROADWAY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10036</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>Investment adviser affiliate</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Auction Preferred Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>94</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Subsidiary</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <remarks>The preferred shares reported herein represent the Reporting Person's combined holdings in multiple series of auction preferred securities of the Issuer, which are treated herein as one class of securities in accordance with the Auction Rate Securities - Global Exemptive Relief no-action letter issued by the Securities and Exchange Commission (the &quot;SEC&quot;) on September 22, 2008 (the &quot;Letter&quot;). The Reporting Person undertakes to provide, upon request by the SEC staff, the Issuer, or a security holder of the Issuer, complete information regarding the number of such preferred shares purchased and sold for cash at par (plus dividends, if any) at each different date after the date hereof and not reported on Form 4 in accordance with the Letter. The reporting person is an affiliate of the Issuer's investment adviser.</remarks>

    <ownerSignature>
        <signatureName>/s/ Joseph Maehr</signatureName>
        <signatureDate>2021-03-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
