Champaign is a city in Champaign County, Illinois, United States. The population was 88,302 at the 2020 census. It is the tenth-most populous municipality in Illinois and the fourth most populous city in the state outside the Chicago metropolitan area. It is a principal city of the Champaign–Urbana metropolitan area, which had 236,000 residents in 2020.

Champaign County is a county in the U.S. state of Illinois. As of the 2020 Census, its population was 205,865, making it the 10th-most populous county in Illinois. Its county seat is Urbana.