Shelbyville is a city in Shelby County, Illinois, along the Kaskaskia River. The population was 4,971 at the 2000 census, with a 2009 U.S. Census population estimate of 4,647. It is the county seat of Shelby County. Shelby Memorial Hospital, located in town, is the county's only hospital.
Shelbyville is located at 39°24′29″N 88°47′59″W / 39.40806°N 88.79972°W / 39.40806; -88.79972 (39.408142, -88.799730).
According to the United States Census Bureau, the city has a total area of 3.9 square miles (10.0 km²), of which, 3.7 square miles (9.6 km²) of it is land and 0.2 square miles (0.5 km²) of it (4.90%) is water.