<SEC-DOCUMENT>0001562180-23-000904.txt : 20230203
<SEC-HEADER>0001562180-23-000904.hdr.sgml : 20230203
<ACCEPTANCE-DATETIME>20230203160553
ACCESSION NUMBER:		0001562180-23-000904
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20230201
FILED AS OF DATE:		20230203
DATE AS OF CHANGE:		20230203

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Aigotti Diane
		CENTRAL INDEX KEY:			0001329194

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-02328
		FILM NUMBER:		23585771

	MAIL ADDRESS:	
		STREET 1:		C/O PRIVATEBANCORP,INC.
		STREET 2:		120 SOUTH LASALLE STREET - LEGAL DEPT.
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60603

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			GATX CORP
		CENTRAL INDEX KEY:			0000040211
		STANDARD INDUSTRIAL CLASSIFICATION:	TRANSPORTATION SERVICES [4700]
		IRS NUMBER:				361124040
		STATE OF INCORPORATION:			NY
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		233 SOUTH WACKER DRIVE
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606-7147
		BUSINESS PHONE:		3126216200

	MAIL ADDRESS:	
		STREET 1:		233 SOUTH WACKER DRIVE
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606-7147

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	GENERAL AMERICAN TRANSPORTATION CORP
		DATE OF NAME CHANGE:	19750722
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primarydocument.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2023-02-01</periodOfReport>

    <notSubjectToSection16>false</notSubjectToSection16>

    <issuer>
        <issuerCik>0000040211</issuerCik>
        <issuerName>GATX CORP</issuerName>
        <issuerTradingSymbol>GATX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001329194</rptOwnerCik>
            <rptOwnerName>Aigotti Diane</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O 233 S. WACKER DR.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60606</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isOfficer>false</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2023-02-01</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>268.00</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>106.59</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>14350.00</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents additional shares of phantom stock/RSUs credited to the reporting person's account under the GATX Directors' Phantom Stock Plan (&quot;Phantom Stock Plan&quot;) and the Directors' Deferred Fee Plan (&quot;Deferred Fee Plan&quot;) credited on the transaction date. Each share of phantom stock/RSU represents the right to receive one share of Issuer's common stock upon settlement. The shares of phantom stock/RSUs are generally payable on a deferred basis in common stock at the election of the reporting person upon the reporting person's termination of service on the Issuer's board of directors.</footnote>
        <footnote id="F2">Represents (a) 69 shares acquired pursuant to the dividend reinvestment feature of the Phantom Stock Plan and the Deferred Fee Plan, and (b) 198 shares acquired under the Deferred Fee Plan resulting from the reporting person's election to defer the annual director retainer fees payable to the reporting person in the form of phantom stock/RSUs under the Deferred Fee Plan.</footnote>
    </footnotes>

    <remarks>Exhibit List:

Exhibit 1 -

Confirming Statement</remarks>

    <ownerSignature>
        <signatureName>Lisa M. Ibarra, by Power of Attorney on behalf of Diane M. Aigotti</signatureName>
        <signatureDate>2023-02-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24
<SEQUENCE>2
<FILENAME>dma-confirmingstatement.txt
<DESCRIPTION>CONFIRMING STATEMENT DMA
<TEXT>
Exhibit 1



CONFIRMING STATEMENT



This Statement confirms that the undersigned, Diane M. Aigotti,
has authorized and designated Brian L. Glassberg, Alan R.
Haguewood and Lisa M. Ibarra to execute and file on the
undersigneds behalf all Forms 3, 4 and 5 (including any
amendments thereto) that the undersigned may be required to file
with the U.S. Securities and Exchange Commission as a result of
the undersigneds ownership of or transactions in securities of
GATX Corporation. The authority of Brian L. Glassberg, Alan R.
Haguewood and Lisa M. Ibarra under this Statement shall continue
until the undersigned is no longer required to file Forms 3, 4
and 5 with regard to the undersigneds ownership of or
transactions in securities of GATX Corporation, unless earlier
revoked in writing. The undersigned acknowledges that neither
Brian L. Glassberg, nor Alan R. Haguewood nor Lisa M. Ibarra is
assuming any of the undersigneds responsibilities to comply with
Section 16 of the Securities Exchange Act of 1934.



Date: January 22, 2023



/s/ Diane M. Aigotti
Diane M. Aigotti
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
