Ohio Revised Code Title XXXV. Elections § 3521.02

When a vacancy occurs in the representation of this state in the senate of the United States by death, resignation, or otherwise, the vacancy shall be filled forthwith by appointment by the governor who may appoint some suitable person having the necessary qualifications for senator. The appointee shall hold office until the fifteenth day of December succeeding the next regular state election that occurs more than one hundred eighty days after the vacancy happens. At that next regular state election, a special election to fill the vacancy shall be held, provided, that when the unexpired term ends within one year immediately following the date of such regular state election, an election to fill the unexpired term shall not be held, and the appointment shall be for the unexpired term. The special election shall be governed in all respects by the laws controlling regular state elections for such office. Candidates to be voted for at the special election shall be nominated in the same manner as is provided for the nomination of candidates at regular state elections.

At least one hundred eighty days prior to the date of such regular state election, the governor shall issue a writ directing that a special election be held to fill such vacancy as provided in this section. The writ shall be directed to the secretary of state and a copy of the writ sent by mail to the board of elections of each county in the state which shall give notice of the time and place of holding such special election in the same manner and at the same time provided in section 3501.03 of the Revised Code for giving similar notice for regular elections.