Ohio Rev. Code § 709.30
The legislative authority of a city to which the annexation of another city or village or part thereof is sought as provided in sections 709.22 to 709.29, inclusive, of the Revised Code, may by ordinance, and the board of education of a city school district to which the annexation of another city school district, exempted village school district, or local school district containing a village is sought as provided in such sections may by resolution, assent to such annexation and waive the submission of such question to the electors of the city or district to which such annexation is proposed. If, within thirty days of the passage or adoption of such ordinance or resolution, a petition, signed by twenty-five per cent of the voters of such district or city, is filed requesting that such election be held, such waiver shall be of no effect, and provision shall be made for the holding of such election as provided in section 709.29 of the Revised Code. Such petition shall be filed with the board of elections, and upon finding such a petition sufficient such board of elections shall notify the legislative authority or board of education affected thereby, and shall prepare to conduct such election.
R.C. §709.30