| Edward E. Cox | | Democratic | 1924 | Incumbent re-elected. | nowrap | |- ! | Stephen Pace | | Democratic | 1936 | Incumbent re-elected. | nowrap | |- ! | Albert Sidney Camp | | Democratic | 1939 | Incumbent re-elected. | nowrap | |- ! | Robert Ramspeck | | Democratic | 1929 | Incumbent re-elected. | nowrap | |- ! | Carl Vinson | | Democratic | 1914 | Incumbent re-elected. | nowrap | |- ! | Malcolm C. Tarver | | Democratic | 1926 | Incumbent re-elected. | nowrap | |- ! | Florence Reville Gibbs | | Democratic | 1940 | | Incumbent retired.New member elected.Democratic hold. | nowrap | |- ! | B. Frank Whelchel | | Democratic | 1934 | Incumbent re-elected. | nowrap | |- ! | Paul Brown | | Democratic | 1933 | Incumbent re-elected. | nowrap | |} Idaho |- ! | Compton I. White | | Democratic | 1932 | Incumbent re-elected. | nowrap | |- ! | Henry Dworshak | | Republican | 1938 | Incumbent re-elected. | nowrap | |} Illinois |- ! | Arthur Wergs Mitchell | | Democratic | 1934 | Incumbent re-elected. | nowrap | |- ! | Raymond S. McKeough | | Democratic | 1934 | Incumbent re-elected. | nowrap | |- ! | Edward A. Kelly | | Democratic | 1930 | Incumbent re-elected. | nowrap | |- ! | Harry P. Beam | | Democratic | 1930 | Incumbent re-elected. | nowrap | |- ! | Adolph J. Sabath | | Democratic | 1906 | Incumbent re-elected. | nowrap | |- ! | A. F. Maciejewski | | Democratic | 1938 | Incumbent re-elected. | nowrap | |- ! | Leonard W. Schuetz | | Democratic | 1930 | Incumbent re-elected. | nowrap | |- ! | Leo Kocialkowski | | Democratic | 1932 | Incumbent re-elected. | nowrap | |- ! | James McAndrews | | Democratic | 1934 | | Incumbent lost re-election.New member elected.Republican gain. | nowrap | |- ! | Ralph E. Church | | Republican | 1934 | | Incumbent retired to run for U.S. senator.New member elected.Republican hold. | nowrap | |- ! | Chauncey W. Reed | | Republican | 1934 | Incumbent re-elected. | nowrap | |- ! | Noah M. Mason | | Republican | 1936 | Incumbent