Ohio Revised Code Title XXXV. Elections § 3513.301

(1) That party's candidate for congress;

(2) The candidate for congress of any other major political party under either of the following circumstances:

(B)(1) Except as otherwise provided in division (B)(2) of this section, the boards of elections of all the counties contained in whole or in part within the congressional district for which a special election is being held under this section shall conduct the special election on a date designated by the secretary of state and give notice of the time and places of holding the election as provided in section 3501.03 of the Revised Code. The election shall be held and conducted and returns of it made as in the case of a primary election, except that the secretary of state shall designate the deadline to file a declaration of candidacy or a declaration of intent to be a write-in candidate for the election.

(2) If, for each nomination to be made at the special election to be held under division (B)(1) of this section, only one person has filed a valid declaration of candidacy or no person has filed a valid declaration of candidacy, then no special election shall be held. If no special election is held, then for each nomination for which only one person has filed a valid declaration of candidacy, the secretary of state, upon receiving certification of that fact from the board of elections of the most populous county of the congressional district, shall issue a certificate of nomination to the person and the person's name shall appear on the ballot as that party's candidate at the general election.