Ohio Rev. Code Ann. § 707.29 – Incorporation of city

(A) Cities may be incorporated in the manner provided in sections 707.29 and 707.30 of the Revised Code. Application for incorporation of a city shall be made by petition addressed to the board of county commissioners. The territory proposed for incorporation as a city shall meet all of the following criteria:
1. (1) It shall consist of not less than four square miles.
2. (2) It shall have a population of not less than twenty-five thousand and a population density of at least one thousand persons per square mile.
3. (3) It shall have an assessed valuation of real, personal, and public utility property subject, except as otherwise provided in division (A)(3) of this section, to general property taxation of at least twenty-five hundred dollars per capita. In determining per capita assessed valuation under division (A)(3) of this section, the assessed valuation of any tangible personal property, buildings, structures, improvements, and fixtures that are exempt from taxation under division (B) of section 5709.081 of the Revised Code shall be added to the assessed valuation of real, personal, and public utility property subject to general property taxation.
4. (4) It shall not completely surround an existing municipal corporation.
5. (5) It shall be contiguous.
(B) No territory within the boundaries of a military base, camp, or similar installation under the jurisdiction of a military department of the United States government, that is used for the housing of members of the armed forces of the United States and is a center for military operations of the department shall be incorporated without the approval of the secretary of defense of the United States, his designee , or other person having authority under federal law to give such approval.