Johnsville, also known as Shauck, is an unincorporated community in northern Perry Township, Morrow County, Ohio, United States. It is served by the Shauck post office, with the ZIP code 43349. It is located at the intersection of U.S. Route 42 with State Route 314.
Johnsville was laid out in 1834 and named for John Ely, proprietor. The post office in Johnsville is called Shauck. This post office was established in 1824.