| CONGRESS | SENATOR | TERM BEGAN | TERM ENDED | COMMENTS |
|---|---|---|---|---|
| Class 1 | ||||
| 31st | John C. Fremont (D) | Sept. 9, 1850 | Mar. 3, 1851 | |
| 32nd-34th | John B. Weller (D) | Jan. 30, 1852 | Mar. 3, 1857 | |
| 35th-36th | David C. Broderick (D) | Mar. 4, 1857 | Sept. 16, 1859 | Died |
| 36th | Henry P. Haun (D) | Nov. 3, 1859 | Mar. 4, 1860 | Appointed |
| 36th-37th | Milton S. Latham (D) | Mar. 5, 1860 | Mar. 3, 1863 | |
| 38th-40th | John Conness (R) | Mar. 4, 1863 | Mar. 3, 1869 | |
| 41st-43rd | Eugene Casserly (D) | Mar. 4, 1869 | Nov. 29, 1873 | Resigned |
| 43rd | John S. Hager (D) | Dec. 23, 1873 | Mar. 3, 1875 | |
| 44th-46th | Newton Booth (IR, R) | Mar. 4, 1875 | Mar. 3, 1881 | |
| 47th-49th | John F. Miller (R) | Mar. 4, 1881 | Mar. 8, 1886 | Died |
| 49th | George Hearst (D) | Mar. 23, 1886 | Aug. 4, 1886 | Appointed |
| 49th | Abram P. Williams (R) | Aug. 4, 1886 | Mar. 3, 1887 | |
| 50th-51st | George Hearst (D) | Mar. 4, 1887 | Feb. 28, 1891 | Died |
| 52nd | Charles N. Felton (R) | Mar. 19, 1891 | Mar. 3, 1893 | |
| 53rd-55th | Stephen M. White (D) | Mar. 4, 1893 | Mar. 3, 1899 | |
| 56th-58th | Thomas R. Bard (R) | Feb. 7, 19001 | Mar. 3, 1905 | |
| 59th-61st | Frank P. Flint (R) | Mar. 4, 1905 | Mar. 3, 1911 | |
| 62nd-64th | John D. Works (R) | Mar. 4, 1911 | Mar. 3, 1917 | |
| 65th-79th | Hiram W. Johnson (R) | Mar. 16, 19172 | Aug. 6, 1945 | Died |
| 79th-85th | William F. Knowland (R) | Aug. 26, 1945 | Jan. 3, 1959 | Appointed, then elected |
| 86th-88th | Clair Engle (D) | Jan. 3, 1959 | Jul. 30, 1964 | Died |
| 88th | Pierre E. G. Salinger (D) | Aug. 4, 1964 | Dec. 31, 1964 | Appointed; resigned |
| 88th-91st | George L. Murphy (R) | Jan. 1, 19653 | Jan. 2, 1971 | Resigned |
| 91st-94th | John V. Tunney (D) | Jan. 2, 19714 | Jan. 1, 1977 | Resigned |
| 94th-97th | Samuel I. Hayakawa (R) | Jan. 2, 19775 | Jan. 3, 1983 | |
| 98th-102nd | Pete Wilson (R) | Jan. 3, 1983 | Jan. 7, 1991 | Resigned |
| 102nd | John Seymour (R) | Jan. 7, 1991 | Nov. 3, 1992 | Appointed |
| 102nd-118th | Dianne Feinstein (D) | Nov. 4, 1992 | Sept. 29, 2023 | Died |
| 118th- | Laphonza R. Butler (D) | Oct. 3, 2023 | Present | Appointed |
| Class 3 | ||||
| 31st-33rd | William M. Gwin6 (D) | Sept. 9, 1850 | Mar. 3, 1861 | |
| 37th-39th | James A. McDougall (D) | Mar. 4, 1861 | Mar. 3, 1867 | |
| 40th-42nd | Cornelius Cole (R) | Mar. 4, 1867 | Mar. 3, 1873 | |
| 43rd-45th | Aaron A. Sargent (R) | Mar. 4, 1873 | Mar. 3, 1879 | |
| 46th-48th | James T. Farley (D) | Mar. 4, 1879 | Mar. 3, 1885 | |
| 49th-51st | Leland Stanford (R) | Mar. 4, 1885 | Jun. 21, 1893 | Died |
| 51st-63rd | George C. Perkins (R) | Jul. 26, 1893 | Mar. 3, 1915 | Appointed, then elected |
| 64th-66th | James D. Phelan (D) | Mar. 4, 1915 | Mar. 3, 1921 | |
| 67th-72nd | Samuel M. Shortridge (R) | Mar. 4, 1921 | Mar. 3, 1933 | |
| 73rd-75th | William Gibbs McAdoo (D) | Mar. 4, 1933 | Nov. 8, 1938 | Resigned |
| 75th-76th | Thomas M. Storke (D) | Nov. 9, 1938 | Jan. 3, 1939 | Appointed |
| 77th-81st | Sheridan Downey (D) | Jan. 3, 1939 | Nov. 30, 1950 | Resigned |
| 81st-82nd | Richard M. Nixon (R) | Dec. 1, 19507 | Jan. 1, 1953 | Resigned |
| 82nd-90th | Thomas H. Kuchel (R) | Jan. 2, 1953 | Jan. 3, 1969 | Appointed, then elected |
| 91st-102nd | Alan Cranston (D) | Jan. 3, 1969 | Jan. 3, 1993 | |
| 103rd-114th | Barbara Boxer (D) | Jan. 3, 1993 | Jan. 3, 2017 | |
| 115th-117th | Kamala Harris (D) | Jan. 3, 2017 | Jan. 18, 20218 | Resigned |
| 117th- | Alejandro Padilla (D) | Jan. 18, 2021 | Present | Appointed, then elected |
1. Vacancy from Mar. 4, 1899, to Feb. 6, 1900, because of failure of legislature to elect.
2. Elected for the term beginning Mar. 4, 1917. Remained governor during interim.
3. Appointed to the term ending Jan. 3, 1965, having previously been elected to the term beginning on that day.
4. Appointed to the term ending Jan. 3, 1971, having previously been elected to the term beginning on that day.
5. Appointed to the term ending Jan. 3, 1977, having previously been elected to the term beginning on that day.
6. Seat vacant between Mar. 3, 1855 and Jan. 13, 1857 due to failure of legislature to elect.
7. Appointed to the term ending Jan. 3, 1951, having previously been elected to the term beginning on that day. Resigned effective Jan. 1, 1953, having been elected Vice President of the United States on Nov. 4, 1952.
8. Resigned Jan. 18, 2021, having been elected Vice President of the United States on Nov. 3, 2020.
