Illinois circuit courts

The Illinois circuit courts are state courts of the U.S. state of Illinois. They are trial courts of original jurisdiction. There are 24 judicial circuits in the state, each comprising one or more of Illinois' 102 counties. The jurisdiction of six of these circuits courts are solely within the confines of a single county; these are Cook, Kane, Will, DuPage, Lake, and McHenry (all Chicago metropolitan area counties). The other 18 circuits each contain between two and 12 counties.

The circuit court has general jurisdiction and can decide, with few exceptions, any kind of case. (The exceptions are redistricting of the Illinois General Assembly and the ability of the governor of Illinois to serve or resume office.) The circuit court also shares jurisdiction with the Supreme Court of Illinois (the state supreme court) to hear cases relating to revenue, mandamus, prohibition, and habeas corpus. However, if the supreme court chooses to exercise its jurisdiction over these cases, the circuit court may not decide them. The circuit court also reviews administrative decisions of certain state agencies.