Old Fort, Ohio
Old Fort is a census-designated place located in northern Pleasant Township, Seneca County, Ohio, United States. It has a post office with the ZIP code 44861. Old Fort was platted in 1882, and named after Fort Seneca, a fort built during the War of 1812. A post office has been in operation at Old Fort since 1882. Old Fort High School is located on County Road 51. Geography. Old Fort sits adjacent to the Sandusky River, which is a tributary to Lake Erie.