Clarksville is a village in Clinton County, Ohio, United States. The population was 497 at the 2000 census. It is served by the Clinton Massie branch of the Wilmington Public Library of Clinton County.
Clarksville is located at 39°24′11″N 83°58′57″W / 39.40306°N 83.9825°W / 39.40306; -83.9825 (39.403035, -83.982541).
According to the United States Census Bureau, the village has a total area of 0.5 square miles (1.3 km²), all of it land.