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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 E6fjFj+SLFiqNf0uo7/2wClJ80DQYNrV4pSxPpjBBkEgGyJERS2/f+58r15reI6j
 3fsJ0euH4SfQHxMC6Uj2vg==

<SEC-DOCUMENT>0000073124-04-000113.txt : 20041026
<SEC-HEADER>0000073124-04-000113.hdr.sgml : 20041026
<ACCEPTANCE-DATETIME>20041026135543
ACCESSION NUMBER:		0000073124-04-000113
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20041022
FILED AS OF DATE:		20041026
DATE AS OF CHANGE:		20041026

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NORTHERN TRUST CORP
		CENTRAL INDEX KEY:			0000073124
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				362723087
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		50 S LASALLE ST
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60675
		BUSINESS PHONE:		3126306000

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	NORTRUST CORP
		DATE OF NAME CHANGE:	19780525

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			PERO PERRY R
		CENTRAL INDEX KEY:			0001188085

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-05965
		FILM NUMBER:		041096148

	BUSINESS ADDRESS:	
		STREET 1:		50 S LA SALLE ST
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60675
		BUSINESS PHONE:		3126306000

	MAIL ADDRESS:	
		STREET 1:		50 S LA SALLE ST
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60675
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-10-22</periodOfReport>

    <issuer>
        <issuerCik>0000073124</issuerCik>
        <issuerName>NORTHERN TRUST CORP</issuerName>
        <issuerTradingSymbol>NTRS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001188085</rptOwnerCik>
            <rptOwnerName>PERO PERRY R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1></rptOwnerStreet1>
            <rptOwnerStreet2>50 S. LA SALLE ST.</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60675</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice Chairman</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2004-10-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3402</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>39.755</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>97456</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-10-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1131</value>
                    <footnoteId id="F4"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>39.755</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>648284</value>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>89821</value>
                    <footnoteId id="F6"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>401(k)</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15443</value>
                    <footnoteId id="F7"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>ESOP</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents stock units payable automatically on a 1-for-1 basis in shares of the Corporation's common stock.</footnote>
        <footnote id="F2">Stock units (3,402) withheld in payment of taxes due upon the vesting of 16,000 stock units.  Reporting person is deferring receipt of 4,681 stock units and taking a distribution of the balance of 7,917 stock units.</footnote>
        <footnote id="F3">Total represents the distribution of 11,319 stock units as described in Footnote 2.</footnote>
        <footnote id="F4">Mature shares surrendered in payment of an additional 10 percent in taxes relating to the distribution of stock units as described in Footnote 2.</footnote>
        <footnote id="F5">Total reflects the distribution of 7,917 stock units as shares of common stock as described in Footnote 2.</footnote>
        <footnote id="F6">as of 09/30/2004</footnote>
        <footnote id="F7">as of 12/31/2003</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Eileen C. Ratzka POA for Perry R. Pero</signatureName>
        <signatureDate>2004-10-26</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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