Haydenville is an unincorporated community and census-designated place in southern Green Township, Hocking County, Ohio, United States. As of the 2020 census the population of the CDP was 337. Haydenville was founded in 1852. The community was named for Peter Hayden, the original owner of the town site. A post office has been in operation at …Haydenville is an unincorporated community and census-designated place in southern Green Township, Hocking County, Ohio, United States. As of the 2020 census the population of the CDP was 337. Haydenville was founded in 1852. The community was named for Peter Hayden, the original owner of the town site. A post office has been in operation at Haydenville since 1870.