-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 FcgXVnF6QONgFyDIagCqqHZWYfDO+FEYpOjDGxw0pKqzaGotmnS4Dx75D5geNbRQ
 ZmdBmKhxLlmv2JaX4qNNAA==

<SEC-DOCUMENT>0000093751-09-000031.txt : 20090306
<SEC-HEADER>0000093751-09-000031.hdr.sgml : 20090306
<ACCEPTANCE-DATETIME>20090306183656
ACCESSION NUMBER:		0000093751-09-000031
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090305
FILED AS OF DATE:		20090306
DATE AS OF CHANGE:		20090306

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			OLeary David C
		CENTRAL INDEX KEY:			0001322708

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-07511
		FILM NUMBER:		09664450

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		617 786-3000

	MAIL ADDRESS:	
		STREET 1:		STATE STREET CORPORATION
		STREET 2:		ONE LINCOLN STREET
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02111

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			STATE STREET Corp
		CENTRAL INDEX KEY:			0000093751
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				042456637
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		ONE LINCOLN STREET
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02111
		BUSINESS PHONE:		617 786-3000

	MAIL ADDRESS:	
		STREET 1:		ONE LINCOLN STREET
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02111

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	STATE STREET CORP
		DATE OF NAME CHANGE:	19970424

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	STATE STREET BOSTON FINANCIAL CORP
		DATE OF NAME CHANGE:	19780525
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-03-05</periodOfReport>

    <issuer>
        <issuerCik>0000093751</issuerCik>
        <issuerName>STATE STREET Corp</issuerName>
        <issuerTradingSymbol>STT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001322708</rptOwnerCik>
            <rptOwnerName>OLeary David C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>STATE STREET CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>ONE LINCOLN STREET</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02111</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>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-03-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>18889</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>57843</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-03-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5998</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>19.31</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>51845</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Settlement of a performance award granted on February 15, 2007 as part of 2006 compensation.</footnote>
        <footnote id="F2">These shares were withheld to satisfy tax withholding obligations in connection with the settlement of a performance award granted on February 15, 2007 as part of 2006 compensation.</footnote>
        <footnote id="F3">The balance reflects the amount of shares beneficially owned, including shares received due to dividend reinvestment, as of the date of this report.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Shannon C. Stanley, Attorney-in-fact</signatureName>
        <signatureDate>2009-03-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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