Sisseton is a city in Roberts County, South Dakota, United States. The population was 2,479 at the 2020 census. It is the county seat of Roberts County. Sisseton is home to several tourist attractions

Roberts County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 10,280. Its county seat is Sisseton. The county was named for S. G. Roberts of Fargo, North Dako