The 55th Illinois General Assembly met from 1927 to 1929.

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

[a] Richard J. Barr of Joliet was President pro tempore of the Senate.

Robert Scholes of Peoria was the Speaker of the House of Representatives.

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