Carterville is a city in Williamson County, Illinois, United States. At the 2020 census, the city's population was 5,848. The city is part of the Carbondale-Marion-Herrin combined statistical area and has grown considerably as a residential community of Carbondale and Marion. Carterville is considered a reliably Republican city. The city of Carterville backed President Trump, 61%-37%, in the 2024 Presidential Election.