The Illinois State Bar Association (ISBA) is among largest voluntary state bar associations in the United States. Approximately 28,000 lawyers are members of the ISBA. Unlike some state bar associations, in which membership is mandatory, ISBA membership is not required of lawyers licensed to practice in Illinois and ISBA membership is completely voluntary. The ISBA is headquartered in Springfield, Illinois. It also has an office in Chicago, Illinois.

The Supreme Court of Illinois is the state supreme court, the highest court of the judiciary of Illinois. The court's authority is granted in Article VI of the current Illinois Constitution, which provides for seven justices elected from the five appellate judicial districts of the state: three justices from the First District and one from each of the other four districts. Absent mid-term vacancy, each justice is elected for a term of ten years, which may be renewed and the chief justice is elected by the court from its members for a three-year term.