Ohio Rev. Code § 2727.03: Courts authorized to grant injunctions.

At the beginning of an action, or any time before judgment, an injunction may be granted by the supreme court or a judge thereof, the court of appeals or a judge thereof in his district, the court of common pleas or a judge thereof in his county, or the probate court, in causes pending therein, when it appears to the court or judge by affidavit of the plaintiff, or his agent, that the plaintiff is entitled to an injunction.

On like grounds and proof, the probate judge may grant injunctions in actions pending in either the court of common pleas or court of appeals of his county, in the absence therefrom of the judges of such courts.