There were elections in 1903 to the United States House of Representatives:
Elections are listed by date and district.
|- ! | Nicholas Muller | | 1876<br/>1880 <small>(retired)</small><br/>1882<br/>1886 <small>(retired)</small><br/>1898 | |Incumbent resigned November 2, 1901.<br/>Republican gain. | nowrap|
|- ! | James Joseph Butler | | 1900<br/>1902 <small>(seat declared vacant)</small><br/>1902 <small>(special)</small> | |Election successfully challenged.<br/>Republican gain. | nowrap|
Elections are listed by date and district.
|- ! | Joseph J. Gill | | 1899 | |Incumbent resigned October 31, 1903.<br/>New member elected November 3, 1903.<br/>Republican hold. | nowrap|
|- ! | Robert H. Foerderer | | 1900 | |Incumbent died July 26, 1903.<br/>New member elected November 3, 1903.<br/>Republican hold. | nowrap|
|- ! | Thomas H. Ball | | 1896 | |Incumbent resigned November 16, 1903.<br/>New member elected November 17, 1903.<br/>Democratic hold. | nowrap|
|- ! | colspan=3 |Vacant | |Incumbent Chester I. Long (R) resigned to take a U.S. Senate seat.<br/>New member elected May 26, 1903.<br/>Republican hold. | nowrap|
|- ! | colspan=3 |Vacant | |Incumbent Thomas H. Tongue (R) died January 11, 1903.<br/>New member elected June 1, 1903.<br/>Republican hold. | nowrap|
|- ! | Vincent Boreing | | 1898 | |Incumbent died September 16, 1903.<br/>New member elected November 10, 1903.<br/>Republican hold. | nowrap|