Chamberlain is a city in Brule County, South Dakota, United States. The population was 2,387 at the 2010 census. It is the county seat of Brule County. Chamberlain is home to the Akta Lakota Museum and Cultural Center, which profiles the lives of nomadic Plains Indians. Chamberlain is also the home of the South Dakota Hall of Fame. According to the United States Census Bureau, the city has a total area of 7.84 square miles (20.31 km²), of which, 6.64 square miles (17.21 km²) of it is land and 1.2 square miles (3.1 km²) is water.