Johnstown is a village in Licking County, Ohio, United States. The population was 4,632 at the 2010 census.
Johnstown was the home of William A. Ashbrook, an American businessman, newspaper publisher, and Democratic politician from Ohio. His son, John Ashbrook, was elected to the Ohio House of Representatives in 1956, and in 1960 won his father's old seat in the U.S. House of Representatives as the Republican candidate. In the 1972 presidential election, John Ashbrook ran against incumbent Richard Nixon in some state primaries as an alternative conservative candidate.