Columns: District | Vacator | Reason for change | Successor | Date successor seated
Louisiana 7th | T. Ashton Thompson (D) | Died July 1, 1965 | Edwin Edwards (D) | October 2, 1965 | Ohio 7th | Clarence J. Brown (R) | Died August 23, 1965 | Bud Brown (R) | November 2, 1965 | North Carolina 1st | Herbert C. Bonner (D) | Died November 7, 1965 | Walter B. Jones, Sr. (D) | February 5, 1966 | Texas 8th | Albert R. Thomas (D) | Died February 15, 1966 | Lera M. Thomas (D) | March 26, 1966 | California 14th | John F. Baldwin, Jr. (R) | Died March 9, 1966 | Jerome R. Waldie (D) | June 7, 1966 | Alaska At-large | Ralph J. Rivers (D) | Resigned December 30, 1966 | Vacant | Not filled this term | Indiana 8th | Winfield K. Denton (D) | Resigned December 30, 1966 | Vacant | Not filled this term | Indiana 10th | Ralph Harvey (R) | Resigned December 30, 1966 | Vacant | Not filled this term | New York 29th | Leo W. O'Brien (D) | Resigned December 30, 1966 | Vacant | Not filled this term | North Carolina 4th | Harold D. Cooley (D) | Resigned December 30, 1966 | Vacant | Not filled this term | Ohio 15th | Robert T. Secrest (D) | Resigned December 30, 1966 | Vacant | Not filled this term | Pennsylvania 9th | Paul B. Dague (R) | Resigned December 30, 1966 | Vacant | Not filled this term | Pennsylvania 16th | John C. Kunkel (R) | Resigned December 30, 1966 | Vacant | Not filled this term | Tennessee 7th | Tom J. Murray (D) | Resigned December 30, 1966 | Vacant | Not filled this term