EXHIBIT 23.1



        CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM


We consent to the incorporation by reference in the Registration Statement
(Form S-8) pertaining to the 2005 Incentive Plan of Ohio Casualty Corporation
of our reports dated March 1, 2005, with respect to the consolidated financial
statements and schedules of Ohio Casualty Corporation included in its Annual
Report (Form 10-K) for the year ended December 31, 2004, Ohio Casualty
Corporation management's assessment of the effectiveness of internal control
over financial reporting, and the effectiveness of internal control over
financial reporting of Ohio Casualty Corporation, filed with the Securities
and Exchange Commission.




 /s/  Ernst & Young LLP


 Cincinnati, Ohio

 May 16, 2005