-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 UZFEEuqMGEDkw342PJkwXA==

<SEC-DOCUMENT>0001179110-06-020125.txt : 20061019
<SEC-HEADER>0001179110-06-020125.hdr.sgml : 20061019
<ACCEPTANCE-DATETIME>20061019173858
ACCESSION NUMBER:		0001179110-06-020125
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20061017
FILED AS OF DATE:		20061019
DATE AS OF CHANGE:		20061019

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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Shapiro A Steven
		CENTRAL INDEX KEY:			0001378192

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33077
		FILM NUMBER:		061154032

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		847-861-6000

	MAIL ADDRESS:	
		STREET 1:		799 CENTRAL AVENUE
		STREET 2:		SUITE 350
		CITY:			HIGHLAND PARK
		STATE:			IL
		ZIP:			60035
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-10-17</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001378192</rptOwnerCik>
            <rptOwnerName>Shapiro A Steven</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>799 CENTRAL AVENUE,</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 350</rptOwnerStreet2>
            <rptOwnerCity>HIGHLAND PARK</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60035</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>2006-10-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>17.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15481</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Mr. Shapiro has a 25% interest in a company that owns 61,924 shares of First Mercury Financial Corporation's common stock. Mr. Shapiro disclaims any beneficial ownership in the shares held by the company, except to the extent of his pecuniary interest therein.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Eric Orsic, as Attorney-In-Fact</signatureName>
        <signatureDate>2006-10-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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