Tyler Smith (R) | September 17, 1969 |- | Illinois(3) | | Ralph Tyler Smith (R) | style="font-size:80%" | Successor elected November 3, 1970 | | Adlai Stevenson III (D) | November 17, 1970 |- | Delaware(1) | | John J. Williams (R) | style="font-size:80%" | Resigned December 30, 1970 | | William Roth (R) | January 1, 1971 |- | California(1) | | George Murphy (R) | style="font-size:80%" | Resigned January 2, 1971 | | John V. Tunney (D) | January 2, 1971 |} House of Representatives Replacements: 14 Democratic: 2 seat net gain Republican: 2 seat net loss Deaths: 10 Resignations: 8 Total seats with changes: 18 |- | | nowrap| Edwin Reinecke (R) | style="font-size:80%" | Resigned January 21, 1969, after becoming Lieutenant Governor of California | nowrap | Barry Goldwater Jr. (R) | April 29, 1969 |- | | nowrap| Melvin Laird (R) | style="font-size:80%" | Resigned January 21, 1969, after being appointed United States Secretary of Defense | nowrap | Dave Obey (D) | April 1, 1969 |- | | nowrap| Fats Everett (D) | style="font-size:80%" | Died January 26, 1969 | nowrap | Ed Jones (D) | March 25, 1969 |- | | nowrap| James F. Battin (R) | style="font-size:80%" | Resigned February 27, 1969, after being appointed judge for the US District Court for the District of Montana | nowrap | John Melcher (D) | June 24, 1969 |- | | nowrap| Donald Rumsfeld (R) | style="font-size:80%" | Resigned May 25, 1969, after being appointed Director of the Office of Economic Opportunity | nowrap | Phil Crane (R) | November 25, 1969 |- | | nowrap| William H. Bates (R) | style="font-size:80%" | Died June 22, 1969 | nowrap | Michael J. Harrington (D) | September 30, 1969 |- | | nowrap| Daniel J. Ronan (D) | style="font-size:80%" | Died August 13, 1969 | nowrap | George W. Collins (D) | November 3, 1970 |- | | nowrap| Charles Samuel Joelson (D) | style="font-size:80%" | Resigned September 4, 1969, after becoming judge of Superior Court of New Jersey | nowrap | Robert A. Roe (D) | November 4, 1969 |- | | nowrap| William T. Cahill (R) | style="font-size:80%" | Resigned January 19, 1970, after becoming Governor of New Jersey | nowrap | Edwin B. Forsythe (R) | November 3, 1970 |- | | nowrap| Glenard P. Lipscomb (R) | style="font-size:80%" | Died