Lemmon is a town in Perkins County, South Dakota, United States. The population was 1,160 at the 2020 census. Lemmon is named after G…Lemmon is a town in Perkins County, South Dakota, United States. The population was 1,160 at the 2020 census. Lemmon is named after George Ed Lemmon, a cattleman, who founded the town in 1906. The City of Lemmon received the South Dakota Community of the Year Award in 2012.