<SEC-DOCUMENT>0001015328-17-000047.txt : 20170130
<SEC-HEADER>0001015328-17-000047.hdr.sgml : 20170130
<ACCEPTANCE-DATETIME>20170130161755
ACCESSION NUMBER:		0001015328-17-000047
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20170126
FILED AS OF DATE:		20170130
DATE AS OF CHANGE:		20170130

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			WINTRUST FINANCIAL CORP
		CENTRAL INDEX KEY:			0001015328
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				363873352
		STATE OF INCORPORATION:			IL
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		9700 WEST HIGGINS ROAD, 8TH FLOOR
		CITY:			ROSEMONT
		STATE:			IL
		ZIP:			60018
		BUSINESS PHONE:		8479399000

	MAIL ADDRESS:	
		STREET 1:		9700 WEST HIGGINS ROAD, 8TH FLOOR
		CITY:			ROSEMONT
		STATE:			IL
		ZIP:			60018

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CRANE TIMOTHY
		CENTRAL INDEX KEY:			0001501874

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35077
		FILM NUMBER:		17557687

	MAIL ADDRESS:	
		STREET 1:		1228 OAK STREET
		CITY:			WINNETKA
		STATE:			IL
		ZIP:			60093
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_148581105143258.xml
<DESCRIPTION>FORM 4
<TEXT>
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    <periodOfReport>2017-01-26</periodOfReport>

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    <issuer>
        <issuerCik>0001015328</issuerCik>
        <issuerName>WINTRUST FINANCIAL CORP</issuerName>
        <issuerTradingSymbol>WTFC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001501874</rptOwnerCik>
            <rptOwnerName>CRANE TIMOTHY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>9700 WEST HIGGINS ROAD, 8TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ROSEMONT</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60018</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EXECUTIVE VICE PRESIDENT</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
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                <value>Common Stock</value>
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            <transactionDate>
                <value>2017-01-26</value>
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                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
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                </sharesOwnedFollowingTransaction>
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                <transactionPricePerShare>
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                <transactionAcquiredDisposedCode>
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        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
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            <transactionDate>
                <value>2017-01-27</value>
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            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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                    <footnoteId id="F3"/>
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                <directOrIndirectOwnership>
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                <natureOfOwnership>
                    <value>By ESPP</value>
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        </nonDerivativeHolding>
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    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Non-Qualified Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>33.28</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2017-01-27</value>
            </transactionDate>
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                <transactionFormType>4</transactionFormType>
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                <transactionShares>
                    <value>1910</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2014-08-03</value>
            </exerciseDate>
            <expirationDate>
                <value>2018-08-03</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1910.0</value>
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                    <value>954</value>
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                <value>Non-Qualified Stock Option (right to buy)</value>
            </securityTitle>
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                <value>30.98</value>
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            <transactionDate>
                <value>2017-01-27</value>
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                <transactionCode>M</transactionCode>
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                    <value>1049</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2015-01-26</value>
            </exerciseDate>
            <expirationDate>
                <value>2019-01-26</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
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            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2097</value>
                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents stock awarded upon attainment of performance objectives under the Company's Long Term Incentive Program.</footnote>
        <footnote id="F2">The price reported is the weighted average price. The shares were sold in multiple transactions at prices ranging from $71.40 to $71.73. The reporting person undertakes to provide to the SEC, the issuer and any security holder full information regarding the number of shares and the prices at which the shares were sold.</footnote>
        <footnote id="F3">Includes 135 shares purchased by reporting person during 2016 in the Company's Employee Stock Purchase Plan.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/Kathleen M. Boege, Attorney-in-fact</signatureName>
        <signatureDate>2017-01-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
