Sisseton is a city locate on the Lake Traverse Indian Reservation in Roberts County, South Dakota, United States. The population was 2,572 at the 2000 census. It is the county seat of Roberts County. Sisseton is home to a number of attractions including the Nicollett Tower and the "Song to the Great Spirit" Building on the campus of Sisseton Wahpeton College. Named after the Sisseton (or Sissetowan) division of the Sioux the city is located a few miles north of the tribal seat of the Sisseton-Wahpeton Sioux Tribe at Old Agency, South Dakota.