There were special elections to the U.S. House of Representatives in 1921.
|- ! | Fred L. Blackmon | | 1910 | | Incumbent died February 8, 1921.<br/>New member elected June 7, 1921.<br/>Democratic hold. | nowrap |
|- ! | Samuel M. Taylor | | 1912 | | Incumbent died September 13, 1921.<br/>New member elected October 25, 1921.<br/>Democratic hold. | nowrap |
|- ! | colspan=3 | Vacant | | Representative-elect Charles F. Van de Water (R) died November 20, 1920.<br/>New member elected February 15, 1921.<br/>Republican hold. | nowrap |
|- ! | James W. Good | | 1908 | | Incumbent resigned June 15, 1921.<br/>New member elected.<br/>Republican hold. | nowrap |
|- ! | Willfred W. Lufkin | | 1917 <small>(special)</small> | | Incumbent resigned June 30, 1921.<br/>New member elected.<br/>Republican hold. | nowrap |
|- ! | William H. Frankhauser | | 1920 | | Incumbent died May 9, 1921.<br/>New member elected June 28, 1921.<br/>Republican hold. | nowrap |
|- ! | Mahlon M. Garland | | 1914 | | Incumbent died November 19, 1920.<br/>New member elected September 20, 1921.<br/>Republican hold. | nowrap |