-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 CMlSqXFzHfbK4TPo/iWvEXPP5sTt8v9O/D7Lh6BTVr2AwlkDbYu1SJEznXjhoS+M
 vs7af6wh+b4lM4ipuq6mKA==

<SEC-DOCUMENT>0001179110-08-015950.txt : 20080825
<SEC-HEADER>0001179110-08-015950.hdr.sgml : 20080825
<ACCEPTANCE-DATETIME>20080825165828
ACCESSION NUMBER:		0001179110-08-015950
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080801
FILED AS OF DATE:		20080825
DATE AS OF CHANGE:		20080825

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Fleckenstein Terrance A
		CENTRAL INDEX KEY:			0001443681

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33077
		FILM NUMBER:		081037166

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		248-358-4010

	MAIL ADDRESS:	
		STREET 1:		29110 INKSTER ROAD
		STREET 2:		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>3
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 3 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0203</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2008-08-01</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001443681</rptOwnerCik>
            <rptOwnerName>Fleckenstein Terrance A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>29110 INKSTER ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SOUTHFIELD</rptOwnerCity>
            <rptOwnerState>MI</rptOwnerState>
            <rptOwnerZipCode>48034</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Claims Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>No securities are beneficially owned.</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <ownerSignature>
        <signatureName>/s/ Terrance A. Fleckenstein</signatureName>
        <signatureDate>2008-08-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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