Roachester is an unincorporated community in Warren County, Ohio, United States. As of the 2020 census, Roachester had a population of 579. Roachester is located at the junction of Ohio State Route 3 and Ohio State Route 123, east of Morrow.
An early variant name was "Salem". Roachester was platted in 1816, and named for James Roach, proprietor. A post office called Rochester was established in 1825, and remained in operation until 1853.