Ohio Revised Code Title XXI. Courts Probate Juvenile § 2105.25

(A) As used in this section and section 2105.26 of the Revised Code:

(B) A man alleging himself to be the father of an adult child, the adult child's mother, and the adult child may appear together before the probate judge of the county in which the man resides and jointly file a declaration stating that the man is the adult child's father and requesting that the court issue an order declaring the man to be the adult child's father. The declaration must state that the adult child's birth certificate does not designate anyone as the adult child's father, the request for the order is made freely and voluntarily by all parties appearing before the court, and genetic test results show the man is the adult child's father. A copy of the birth certificate and the genetic test results must be attached to the declaration.

(C) The man alleging himself to be the adult child's father and the adult child may appear before the court without the adult child's mother and file the declaration if the mother is deceased or has been adjudicated incompetent. If the man alleging himself to be the adult child's father is not a resident of this state, appearance under this section may be made before a probate judge of any county of this state.