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.

The judiciary of Illinois is the unified court system of Illinois primarily responsible for applying the Constitution and law of Illinois. It consists of the Supreme Court, the Appellate Court, and circuit courts. The Supreme Court oversees the administration of the court system.