The 2004 congressional elections in Illinois were held November 2, 2004 to determine who would represent the State of Illinois in the United States House of Representatives.

2004 United States House of Representatives elections in Illinois

← 2002 November 2, 2004 (2004-11-02) 2006 →
All 19 Illinois seats to the United States House of Representatives
Majority party Minority party   Party Democratic Republican Last election 10 9 Seats won 10 9 Seat change Popular vote 2,675,273 2,271,676 Percentage 53.63% 45.54%
Democratic   50–60%   60–70%   70–80%   80–90% Republican   50–60%   60–70%   70–80%

Illinois had nineteen seats in the House, apportioned according to the 2000 United States census. Representatives are elected for two-year terms; those elected would serve in the 109th Congress from January 3, 2005, to January 3, 2007.