Oak Harbor is a village in Ottawa County, Ohio, United States. Oak Harbor is 30 miles east of Downtown Toledo. The population was 2,821 at the 2020 census. It lies a short distance southwest of the Davis-Besse Nuclear Power Station, one of two nuclear power plants in Ohio.

Ottawa County is a county located in the northwestern part of the U.S. state of Ohio. As of the 2020 census, the population was 40,364. Its county seat is Port Clinton. The county is named either for the Ottawa (Odawa) Indigenous peoples who lived there, or for an Indigenous word meaning "trader".