Illinois's 18th congressional district

The district covered parts of McLean, Peoria, Sangamon, Stark and Tazewell counties, and all of Adams, Brown, Cass, Hancock, Logan, Marshall, Mason, McDonough, Menard, Morgan, Pike, Schuyler, Scott and Woodford counties, as of the 2011 redistricting which followed the 2010 census.

All or parts of Bloomington, Chatham, Jacksonville, Lincoln, Macomb, Morton, Normal, Peoria, Quincy and Springfield are included.

Due to Illinois losing population in the 2020 United States census, the district was eliminated in January 2023.

Ray LaHood decided not to seek re-election in 2008 and was chosen by Barack Obama to serve as U.S. Secretary of Transportation.

Illinois State Representative Aaron Schock of Peoria won the seat for the Republicans in the November 4, 2008 election.