Exhibit 31.1
                             CERTIFICATION



I, Dan R. Carmichael, certify that:

   1. I have reviewed this quarterly report on Form 10-Q of Ohio
      Casualty Corporation;

   2. Based on my knowledge, this report does not contain any untrue
      statement of a material fact or omit to state a material fact
      necessary to make the statements made, in light of the
      circumstances under which such statements were made, not
      misleading with respect to the period covered by this report;

   3. Based on my knowledge, the financial statements, and other
      financial information included in this report, fairly present
      in all material respects the financial condition, results of
      operations and cash flows of the registrant as of, and for, the
      periods presented in this report;

   4. The registrant's other certifying officer(s) and I are
      responsible for establishing and maintaining disclosure controls
      and procedures (as defined in Exchange Act Rules 13a-15(e) and
      15d-15(e)) and internal control over financial reporting (as
      defined in exchange Act Rules 13a-15(f) and 15d-15(f)) for the
      Registrant and have:

        (a) Designed such disclosure controls and procedures, or caused
            such disclosure controls and procedures to be designed under our
            supervision, to ensure that material information relating to the
            registrant, including its consolidated subsidiaries, is made known
            to us by others within those entities, particularly during the
            period in which this report is being prepared;

        (b) Designed such internal control over financial reporting, or caused
            such internal control over financial reporting to be designed under
            our supervision, to provide reasonable assurance regarding the
            reliability of financial reporting and the preparation of financial
            statements for external purposes in accordance with generally
            accepted accounting principles;

        (c) Evaluated the effectiveness of the registrant's disclosure controls
            and procedures and presented in this report our conclusions about
            the effectiveness of the disclosure controls and procedures, as of
            the end of the period covered by this report based on such
            evaluation; and

        (d) Disclosed in this report any change in the registrant's internal
            control over financial reporting that occurred during the
            registrant's most recent fiscal quarter (the registrant's fourth
            fiscal quarter in the case of an annual report) that has materially
            affected, or is reasonably likely to materially affect, the
            registrant's internal control over financial reporting; and

   5. The registrant's other certifying officer(s) and I have disclosed, based
      on our most recent evaluation, of internal control over financial
      reporting, to the registrant's auditors and the audit committee of the
      registrant's board of directors (or persons performing the equivalent
      functions):

        (a) All significant deficiencies and material weaknesses in the design
            or operation of internal control over financial reporting which
            are reasonably likely to adversely affect the registrant's ability
            to record, process, summarize and report financial
            information; and

        (b) Any fraud, whether or not material, that involves management or
            other employees who have a significant role in the registrant's
            internal control over financial reporting.





Date:  October 30, 2006                 /s/Dan R. Carmichael
                                        -------------------------------------
                                        Dan R. Carmichael
                                        President and Chief Executive Officer