Sisseton is a city on the Lake Traverse Indian Reservation in Roberts County, South Dakota, United States. The population was 2,470 at the 2010 census. It is the county seat of Roberts County. Sisseton is home to a number of attractions including the Nicollet Tower and is near the "Song to the Great Spirit" building on the campus of Sisseton Wahpeton College. Named for the Sisseton (or Sissetowan) division of the Native American Sioux, the city is located a few miles north of the tribal seat of the Sisseton Wahpeton Oyate at Agency Village, South Dakota.