The 4th Illinois General Assembly, consisting of the Illinois Senate and the Illinois House of Representatives, met from November 15, 1824, to January 18, 1825, and again from January 2, 1826, to January 18, 1826, at The Vandalia State House. The apportionment of seats in the House of Representatives was based on the provisions of the First Illinois Constitution. Political parties were not established in the State at the time. The 4th General Assembly was preceded by the 3rd Illinois General Assembly, and was succeeded by the 5th Illinois General Assembly.