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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 GuwP5mw+HQhrlUUSus5A3KZyCDO0hoyQrDdYronjW/Lr8IzM1i3u5DC0XlfC1dBp
 Ujy9pzoyNo+He8Stj0bctg==

<SEC-DOCUMENT>0001179110-10-008613.txt : 20100513
<SEC-HEADER>0001179110-10-008613.hdr.sgml : 20100513
<ACCEPTANCE-DATETIME>20100513201413
ACCESSION NUMBER:		0001179110-10-008613
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100511
FILED AS OF DATE:		20100513
DATE AS OF CHANGE:		20100513

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Boyer George R III
		CENTRAL INDEX KEY:			0001464328

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33077
		FILM NUMBER:		10830417

	MAIL ADDRESS:	
		STREET 1:		C/O FIRST MERCURY FINANCIAL CORPORATION
		STREET 2:		29110 INKSTER ROAD, SUITE 100
		CITY:			SOUTHFIELD
		STATE:			MI
		ZIP:			48034

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FIRST MERCURY FINANCIAL CORP
		CENTRAL INDEX KEY:			0000929186
		STANDARD INDUSTRIAL CLASSIFICATION:	FIRE, MARINE & CASUALTY INSURANCE [6331]
		IRS NUMBER:				383164336
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		29621 NORTHWESTERN HWY
		STREET 2:		PO BOX 5096
		CITY:			SOUTHFIELD
		STATE:			MI
		ZIP:			48034
		BUSINESS PHONE:		8103584010

	MAIL ADDRESS:	
		STREET 1:		29621 NORTHWESTERN HGWY
		STREET 2:		PO BOX 5096
		CITY:			SOUTHFIELD
		STATE:			MI
		ZIP:			48086
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-05-11</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000929186</issuerCik>
        <issuerName>FIRST MERCURY FINANCIAL CORP</issuerName>
        <issuerTradingSymbol>FMR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001464328</rptOwnerCik>
            <rptOwnerName>Boyer George R III</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O FIRST MERCURY FINANCIAL CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>29110 INKSTER ROAD, SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>SOUTHFIELD</rptOwnerCity>
            <rptOwnerState>MI</rptOwnerState>
            <rptOwnerZipCode>48034</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-05-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2300</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9263</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Transaction represents the grant of restricted stock to the reporting person under the Company's Omnibus Plan. The shares vest immediately, but will not be transferable for one year after the date of grant.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ John A. Marazza, Attorney-In-Fact</signatureName>
        <signatureDate>2010-05-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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