Chamberlain is a city in Brule County, South Dakota, United States. It is located on the eastern bank of the Missouri River, at the dammed section of the Lake Francis Case, close to where it is crossed by Interstate 90. The population of Chamberlain was 2,473 at the 2020 census. It is the county seat of Brule County. Chamberlain is home to the South Dakota Hall of Fame.