Charleston is a city in, and the county seat of, Coles County, Illinois, United States. The population was 17,286, as of the 2020 census. The city is home to Eastern Illinois University and has close ties with its neighbor, Mattoon. Both are principal cities of the Charleston–Mattoon Micropolitan Statistical Area.

Coles County is a county in Illinois. As of the 2020 census, the population was 46,863. Its county seat is Charleston, which is also the home of Eastern Illinois University.