Columns: District | Incumbent | Party | First elected | Result | Candidates
Illinois 3 | Edward A. Kelly | Democratic | 1930 | Lost re-election Republican gain | Fred E. Busbey (R) 51.3% Edward A. Kelly (D) 48.7% | Illinois 5 | Adolph J. Sabath | Democratic | 1906 | Re-elected | Adolph J. Sabath (D) 72.2% Clem Graver (R) 27.8% | Illinois 10 | George A. Paddock | Republican | 1940 | Lost renomination Republican hold | Ralph E. Church (R) 63.0% Jack Bairstow (D) 37.0% | Illinois 13 | Leo E. Allen | Republican | 1932 | Re-elected | Leo E. Allen (R) 79.4% Michael M. Kinney (D) 20.6% | Illinois 18 | Jessie Sumner | Republican | 1938 | Re-elected | Jessie Sumner (R) 62.4% Fred E. Butcher (D) 37.6% | Illinois 20 | James M. Barnes | Democratic | 1938 | Lost re-election Republican gain | Sid Simpson (R) 51.0% James M. Barnes (D) 49.0%