Tuscola is a city in Douglas County, Illinois, United States. The population was 4,480 at the 2010 census. It is the county seat of Douglas County.
Tuscola is located at 39°47′52″N 88°16′54″W (39.797682, -88.281564).
According to the 2010 census, Tuscola has a total area of 2.747 square miles (7.11 km2), of which 2.74 square miles (7.10 km2) (or 99.75%) is land and 0.007 square miles (0.02 km2) (or 0.25%) is water.
The founding Supervisor of Tuscola township was O. C. Hackett, who was elected in 1868. Hackett was elected Supervisor with a majority of only one vote over W. B. Ervin. O. C. Hackett was the grandson of noted Kentucky frontiersman and Boonsborough resident Peter Hackett. O. C. planted Hackett's Grove, a sassafras grove situated on Section 31, Township 16, Range 9, on the east side of the township. This 20-acre (81,000 m2) grove is traversed by a branch of Scattering Fork of the Embarrass River, long known as Hackett's Run. According to the History of Douglas County (1884), the grove had been owned by the Hacketts long before Douglas County came into existence. O.C. Hackett's father, John Hackett, settled in nearby Coles County in 1835. Family legend holds that Abraham Lincoln stayed at the Hackett farm during the Lincoln-Douglas debates of 1858.