The 56th Illinois General Assembly met from 1929 to 1931.

Fred E. Sterling of Rockford was the Lieutenant Governor of Illinois and thus ex officio President of the Senate.

[a] Martin R. Carlson of Moline was President pro tempore of the Senate.

David Shanahan of Chicago was the Speaker of the House of Representatives.

Illinois was divided into 51 districts, each of which elected one Senator and three Representatives.