Fredericktown is an unincorporated community in northeastern St. Clair Township, Columbiana County, Ohio, United States.

[1] It is located at the confluence of the north and middle forks of Little Beaver Creek.

[3] A post office called Saint Clair operated between 1848 and 1918.

[4] Despite its small size, Fredericktown has a number of historic buildings.

These include an unusual octagonal building which was used variously over the years as a general store, a school and the village post office; two churches (one of which was deconsecrated and is now privately owned); several private homes constructed of locally quarried sandstone; several log cabins; a one-room schoolhouse; a number of barns; and the former Stagecoach Inn, which has been a private home for some years.