Ohio Revised Code Title XXXI. Domestic Relations Children § 3105.12

(B)(1) On and after October 10, 1991, except as provided in divisions (B)(2) and (3) of this section, common law marriages are prohibited in this state, and the marriage of a man and woman may occur in this state only if the marriage is solemnized by a person described in section 3101.08 of the Revised Code and only if the marriage otherwise is in compliance with Chapter 3101. of the Revised Code.

(2) Common law marriages that occurred in this state prior to October 10, 1991, and that have not been terminated by death, divorce, dissolution of marriage, or annulment remain valid on and after October 10, 1991.

(3) Common law marriages that satisfy all of the following remain valid on and after October 10, 1991:

(4) On and after October 10, 1991, all references in the Revised Code to common law marriages or common law marital relationships, including the references in sections 2919.25, 3113.31, and 3113.33 of the Revised Code, shall be construed to mean only common law marriages as described in divisions (B)(2) and (3) of this section.