Shelbyville is a city in Shelby County, Illinois, along the Kaskaskia River. As of the 2010 census, the population was at 4700. It is the county seat of Shelby County. Shelby Memorial Hospital, located in town, is the county's only hospital. According to the United States Census Bureau, the city has a total area of 3.9 square miles (10km2), of which, 3.7 square miles (9.6km2) of it is land and 0.2 square miles (0.52km2) of it (4.90%) is water.