Ohio Rev. Code § 3101.15
A person who is not a party to a marriage, when both parties to the marriage are deceased or otherwise unable to correct the certificate of marriage of the parties, and who claims that the facts stated in a certificate of marriage filed in this state are not true may file an application for correction of the certificate in the probate court of the county in which the certificate was filed.
In the application, the applicant shall set forth all of the available facts required on a certificate of marriage and the reasons for making the application, including the reason for the unavailability of the parties to the marriage. The applicant shall verify the application. On the filing of an application under this section, the court may fix a date for a hearing on the application. The date shall not be less than seven days after the filing date. The application shall be supported by the affidavit of at least one person having knowledge of the facts stated in the application, by documentary evidence, or by other evidence as the court considers sufficient. The probate judge may refuse to accept an affidavit or evidence that appears to be submitted for the purpose of falsifying the certificate of marriage. If the probate judge is satisfied that the facts are as stated, the judge shall make an order correcting the certificate of marriage and shall file it in the judge's office.
This section shall not apply to and shall not limit the ability of the parties to a marriage to correct a certificate of marriage in accordance with procedures followed by the probate court.
R.C. § 3101.15