Barnesville is a city in Clay County, Minnesota, United States. The population was 2,563 at the 2010 census. It is considered a bedroom community to the Fargo-Moorhead metro area. Barnesville Potato Days is held there annually in August.
Interstate 94 and Minnesota State Highways 9, 52, and 34 are four of the main arterial routes in the city.
According to the United States Census Bureau, the city has a total area of 2.1 square miles (5.5 km²), of which, 2.1 square miles (5.4 km²) of it is land and 0.04 square miles (0.1 km²) of it (0.94%) is water.