The law of Illinois consists of several levels, including constitutional, statutory, and regulatory law, as well as case law and local law. The Illinois Compiled Statutes (ILCS) form the general statutory law.

The Illinois General Assembly is the legislature of the U.S. state of Illinois. It has two chambers, the Illinois House of Representatives and the Illinois Senate. The General Assembly was created by the first state constitution adopted in 1818. As of 2023, the current General Assembly is the 103rd; the term of an assembly lasts two years.