Hamersville is a village in Brown County, Ohio, United States. The population was 515 at the 2000 census. Hamersville is named after Thomas Hamer, a general in the Mexican-American War.
Hamersville is located at 38°55′8″N 83°59′8″W / 38.91889°N 83.98556°W / 38.91889; -83.98556 (38.918852, -83.985504).
According to the United States Census Bureau, the village has a total area of 0.4 square miles (1.0 km²).0.4 square miles (1.0 km²) of it is land.