# List of United States senators from Wisconsin

Wisconsin was admitted to the Union on May 29, 1848. Its current U.S. senators are Republican Ron Johnson (since 2011) and Democrat Tammy Baldwin (since 2013), making it one of four states to have a split United States Senate delegation. William Proxmire was the state's longest serving senator (served 1957–1989).

## List of senators

| Class 1Class 1 U.S. senators belong to the electoral cycle that has recently been contested in 2006, 2012, 2018, and 2024. The next election will be in 2030. | Class 1Class 1 U.S. senators belong to the electoral cycle that has recently been contested in 2006, 2012, 2018, and 2024. The next election will be in 2030. | Class 1Class 1 U.S. senators belong to the electoral cycle that has recently been contested in 2006, 2012, 2018, and 2024. The next election will be in 2030. | Class 1Class 1 U.S. senators belong to the electoral cycle that has recently been contested in 2006, 2012, 2018, and 2024. The next election will be in 2030. | Class 1Class 1 U.S. senators belong to the electoral cycle that has recently been contested in 2006, 2012, 2018, and 2024. The next election will be in 2030. | Class 1Class 1 U.S. senators belong to the electoral cycle that has recently been contested in 2006, 2012, 2018, and 2024. The next election will be in 2030. | C | Class 3Class 3 U.S. senators belong to the electoral cycle that has recently been contested in 2004, 2010, 2016, and 2022. The next election will be in 2028. | Class 3Class 3 U.S. senators belong to the electoral cycle that has recently been contested in 2004, 2010, 2016, and 2022. The next election will be in 2028. | Class 3Class 3 U.S. senators belong to the electoral cycle that has recently been contested in 2004, 2010, 2016, and 2022. The next election will be in 2028. | Class 3Class 3 U.S. senators belong to the electoral cycle that has recently been contested in 2004, 2010, 2016, and 2022. The next election will be in 2028. | Class 3Class 3 U.S. senators belong to the electoral cycle that has recently been contested in 2004, 2010, 2016, and 2022. The next election will be in 2028. | Class 3Class 3 U.S. senators belong to the electoral cycle that has recently been contested in 2004, 2010, 2016, and 2022. The next election will be in 2028. |
| # | Senator | Party | Dates in office | Electoral history | T | C | T | Electoral history | Dates in office | Party | Senator | # |
| Vacant | Vacant | Vacant | May 29, 1848 – Jun 8, 1848 | Wisconsin elected its senators 10 days after statehood. | 1 | 30th | 1 | Wisconsin elected its senators 10 days after statehood. | May 29, 1848 – Jun 8, 1848 | Vacant | Vacant | Vacant |
| 1 | Henry Dodge | Democratic | Jun 8, 1848 – Mar 3, 1857 | Elected in 1848. | 1 | 30th | 1 | Elected in 1848. | Jun 8, 1848 – Mar 3, 1855 | Democratic | Isaac P. Walker | 1 |
| 1 | Henry Dodge | Democratic | Jun 8, 1848 – Mar 3, 1857 | Elected in 1848. | 1 | 31st | 2 | Re-elected in 1849.Retired. | Jun 8, 1848 – Mar 3, 1855 | Democratic | Isaac P. Walker | 1 |
| 1 | Henry Dodge | Democratic | Jun 8, 1848 – Mar 3, 1857 | Re-elected in 1851.Retired. | 2 | 32nd | 2 | Re-elected in 1849.Retired. | Jun 8, 1848 – Mar 3, 1855 | Democratic | Isaac P. Walker | 1 |
| 1 | Henry Dodge | Democratic | Jun 8, 1848 – Mar 3, 1857 | Re-elected in 1851.Retired. | 2 | 33rd | 2 | Re-elected in 1849.Retired. | Jun 8, 1848 – Mar 3, 1855 | Democratic | Isaac P. Walker | 1 |
| 1 | Henry Dodge | Democratic | Jun 8, 1848 – Mar 3, 1857 | Re-elected in 1851.Retired. | 2 | 34th | 3 | Elected in 1855. Retired. | Mar 4, 1855 – Mar 3, 1861 | Republican | Charles Durkee | 2 |
| 2 | James R. Doolittle | Republican | Mar 4, 1857 – Mar 3, 1869 | Elected in 1857. | 3 | 35th | 3 | Elected in 1855. Retired. | Mar 4, 1855 – Mar 3, 1861 | Republican | Charles Durkee | 2 |
| 2 | James R. Doolittle | Republican | Mar 4, 1857 – Mar 3, 1869 | Elected in 1857. | 3 | 36th | 3 | Elected in 1855. Retired. | Mar 4, 1855 – Mar 3, 1861 | Republican | Charles Durkee | 2 |
| 2 | James R. Doolittle | Republican | Mar 4, 1857 – Mar 3, 1869 | Elected in 1857. | 3 | 37th | 4 | Elected in 1861. | Mar 4, 1861 – Mar 3, 1879 | Republican | Timothy O. Howe | 3 |
| 2 | James R. Doolittle | Republican | Mar 4, 1857 – Mar 3, 1869 | Re-elected in 1863. Retired. | 4 | 38th | 4 | Elected in 1861. | Mar 4, 1861 – Mar 3, 1879 | Republican | Timothy O. Howe | 3 |
| 2 | James R. Doolittle | Republican | Mar 4, 1857 – Mar 3, 1869 | Re-elected in 1863. Retired. | 4 | 39th | 4 | Elected in 1861. | Mar 4, 1861 – Mar 3, 1879 | Republican | Timothy O. Howe | 3 |
| 2 | James R. Doolittle | Republican | Mar 4, 1857 – Mar 3, 1869 | Re-elected in 1863. Retired. | 4 | 40th | 5 | Re-elected in 1867. | Mar 4, 1861 – Mar 3, 1879 | Republican | Timothy O. Howe | 3 |
| 3 | Matthew H. Carpenter | Republican | Mar 4, 1869 – Mar 3, 1875 | Elected in 1869.Lost re-election. | 5 | 41st | 5 | Re-elected in 1867. | Mar 4, 1861 – Mar 3, 1879 | Republican | Timothy O. Howe | 3 |
| 3 | Matthew H. Carpenter | Republican | Mar 4, 1869 – Mar 3, 1875 | Elected in 1869.Lost re-election. | 5 | 42nd | 5 | Re-elected in 1867. | Mar 4, 1861 – Mar 3, 1879 | Republican | Timothy O. Howe | 3 |
| 3 | Matthew H. Carpenter | Republican | Mar 4, 1869 – Mar 3, 1875 | Elected in 1869.Lost re-election. | 5 | 43rd | 6 | Re-elected in 1872.Lost re-election. | Mar 4, 1861 – Mar 3, 1879 | Republican | Timothy O. Howe | 3 |
| 4 | Angus Cameron | Republican | Mar 4, 1875 – Mar 3, 1881 | Elected in 1875.Retired. | 6 | 44th | 6 | Re-elected in 1872.Lost re-election. | Mar 4, 1861 – Mar 3, 1879 | Republican | Timothy O. Howe | 3 |
| 4 | Angus Cameron | Republican | Mar 4, 1875 – Mar 3, 1881 | Elected in 1875.Retired. | 6 | 45th | 6 | Re-elected in 1872.Lost re-election. | Mar 4, 1861 – Mar 3, 1879 | Republican | Timothy O. Howe | 3 |
| 4 | Angus Cameron | Republican | Mar 4, 1875 – Mar 3, 1881 | Elected in 1875.Retired. | 6 | 46th | 7 | Elected in 1879.Died. | Mar 4, 1879 – Feb 24, 1881 | Republican | Matthew H. Carpenter | 4 |
| 4 | Angus Cameron | Republican | Mar 4, 1875 – Mar 3, 1881 | Elected in 1875.Retired. | 6 | 46th | 7 | | Feb 24, 1881 – Mar 14, 1881 | Vacant | Vacant | Vacant |
| 5 | Philetus Sawyer | Republican | Mar 4, 1881 – Mar 3, 1893 | Elected in 1881. | 7 | 47th | 7 | | Feb 24, 1881 – Mar 14, 1881 | Vacant | Vacant | Vacant |
| 5 | Philetus Sawyer | Republican | Mar 4, 1881 – Mar 3, 1893 | Elected in 1881. | 7 | 47th | 7 | Elected to finish Carpenter's term.Retired. | Mar 14, 1881 – Mar 3, 1885 | Republican | Angus Cameron | 5 |
| 5 | Philetus Sawyer | Republican | Mar 4, 1881 – Mar 3, 1893 | Elected in 1881. | 7 | 48th | 7 | Elected to finish Carpenter's term.Retired. | Mar 14, 1881 – Mar 3, 1885 | Republican | Angus Cameron | 5 |
| 5 | Philetus Sawyer | Republican | Mar 4, 1881 – Mar 3, 1893 | Elected in 1881. | 7 | 49th | 8 | Elected in 1885.Lost re-election. | Mar 4, 1885 – Mar 3, 1891 | Republican | John Coit Spooner | 6 |
| 5 | Philetus Sawyer | Republican | Mar 4, 1881 – Mar 3, 1893 | Re-elected in 1887.Retired. | 8 | 50th | 8 | Elected in 1885.Lost re-election. | Mar 4, 1885 – Mar 3, 1891 | Republican | John Coit Spooner | 6 |
| 5 | Philetus Sawyer | Republican | Mar 4, 1881 – Mar 3, 1893 | Re-elected in 1887.Retired. | 8 | 51st | 8 | Elected in 1885.Lost re-election. | Mar 4, 1885 – Mar 3, 1891 | Republican | John Coit Spooner | 6 |
| 5 | Philetus Sawyer | Republican | Mar 4, 1881 – Mar 3, 1893 | Re-elected in 1887.Retired. | 8 | 52nd | 9 | Elected in 1891.Lost renomination. | Mar 4, 1891 – Mar 3, 1897 | Democratic | William F. Vilas | 7 |
| 6 | John L. Mitchell | Democratic | Mar 4, 1893 – Mar 3, 1899 | Elected in 1893.Retired. | 9 | 53rd | 9 | Elected in 1891.Lost renomination. | Mar 4, 1891 – Mar 3, 1897 | Democratic | William F. Vilas | 7 |
| 6 | John L. Mitchell | Democratic | Mar 4, 1893 – Mar 3, 1899 | Elected in 1893.Retired. | 9 | 54th | 9 | Elected in 1891.Lost renomination. | Mar 4, 1891 – Mar 3, 1897 | Democratic | William F. Vilas | 7 |
| 6 | John L. Mitchell | Democratic | Mar 4, 1893 – Mar 3, 1899 | Elected in 1893.Retired. | 9 | 55th | 10 | Elected in 1897. | Mar 4, 1897 – Apr 30, 1907 | Republican | John Coit Spooner | 8 |
| 7 | Joseph V. Quarles | Republican | Mar 4, 1899 – Mar 3, 1905 | Elected in 1899.Retired. | 10 | 56th | 10 | Elected in 1897. | Mar 4, 1897 – Apr 30, 1907 | Republican | John Coit Spooner | 8 |
| 7 | Joseph V. Quarles | Republican | Mar 4, 1899 – Mar 3, 1905 | Elected in 1899.Retired. | 10 | 57th | 10 | Elected in 1897. | Mar 4, 1897 – Apr 30, 1907 | Republican | John Coit Spooner | 8 |
| 7 | Joseph V. Quarles | Republican | Mar 4, 1899 – Mar 3, 1905 | Elected in 1899.Retired. | 10 | 58th | 11 | Re-elected in 1903.Resigned. | Mar 4, 1897 – Apr 30, 1907 | Republican | John Coit Spooner | 8 |
| 8 | Robert M. La Follette | Republican | Jan 4, 1906 – Jun 18, 1925 | Elected in 1905.Did not assume office until Jan 4, 1906 after resigning as Governor of Wisconsin. | 11 | 59th | 11 | Re-elected in 1903.Resigned. | Mar 4, 1897 – Apr 30, 1907 | Republican | John Coit Spooner | 8 |
| 8 | Robert M. La Follette | Republican | Jan 4, 1906 – Jun 18, 1925 | Elected in 1905.Did not assume office until Jan 4, 1906 after resigning as Governor of Wisconsin. | 11 | 60th | 11 | Re-elected in 1903.Resigned. | Mar 4, 1897 – Apr 30, 1907 | Republican | John Coit Spooner | 8 |
| 8 | Robert M. La Follette | Republican | Jan 4, 1906 – Jun 18, 1925 | Elected in 1905.Did not assume office until Jan 4, 1906 after resigning as Governor of Wisconsin. | 11 | 60th | 11 | | Apr 30, 1907 – May 17, 1907 | Vacant | Vacant | Vacant |
| 8 | Robert M. La Follette | Republican | Jan 4, 1906 – Jun 18, 1925 | Elected in 1905.Did not assume office until Jan 4, 1906 after resigning as Governor of Wisconsin. | 11 | 60th | 11 | Elected to finish Spooner's term. | May 17, 1907 – Mar 3, 1915 | Republican | Isaac Stephenson | 9 |
| 8 | Robert M. La Follette | Republican | Jan 4, 1906 – Jun 18, 1925 | Elected in 1905.Did not assume office until Jan 4, 1906 after resigning as Governor of Wisconsin. | 11 | 61st | 12 | Re-elected in 1909.Retired. | May 17, 1907 – Mar 3, 1915 | Republican | Isaac Stephenson | 9 |
| 8 | Robert M. La Follette | Republican | Jan 4, 1906 – Jun 18, 1925 | Re-elected in 1911. | 12 | 62nd | 12 | Re-elected in 1909.Retired. | May 17, 1907 – Mar 3, 1915 | Republican | Isaac Stephenson | 9 |
| 8 | Robert M. La Follette | Republican | Jan 4, 1906 – Jun 18, 1925 | Re-elected in 1911. | 12 | 63rd | 12 | Re-elected in 1909.Retired. | May 17, 1907 – Mar 3, 1915 | Republican | Isaac Stephenson | 9 |
| 8 | Robert M. La Follette | Republican | Jan 4, 1906 – Jun 18, 1925 | Re-elected in 1911. | 12 | 64th | 13 | Elected in 1914.Died. | Mar 4, 1915 – Oct 21, 1917 | Democratic | Paul O. Husting | 10 |
| 8 | Robert M. La Follette | Republican | Jan 4, 1906 – Jun 18, 1925 | Re-elected in 1916. | 13 | 65th | 13 | Elected in 1914.Died. | Mar 4, 1915 – Oct 21, 1917 | Democratic | Paul O. Husting | 10 |
| 8 | Robert M. La Follette | Republican | Jan 4, 1906 – Jun 18, 1925 | Re-elected in 1916. | 13 | 65th | 13 | | Oct 21, 1917 – Apr 18, 1918 | Vacant | Vacant | Vacant |
| 8 | Robert M. La Follette | Republican | Jan 4, 1906 – Jun 18, 1925 | Re-elected in 1916. | 13 | 65th | 13 | Elected in 1918 to finish Husting's term. | Apr 18, 1918 – Mar 3, 1927 | Republican | Irvine Lenroot | 11 |
| 8 | Robert M. La Follette | Republican | Jan 4, 1906 – Jun 18, 1925 | Re-elected in 1916. | 13 | 66th | 13 | Elected in 1918 to finish Husting's term. | Apr 18, 1918 – Mar 3, 1927 | Republican | Irvine Lenroot | 11 |
| 8 | Robert M. La Follette | Republican | Jan 4, 1906 – Jun 18, 1925 | Re-elected in 1916. | 13 | 67th | 14 | Re-elected in 1920.Lost renomination. | Apr 18, 1918 – Mar 3, 1927 | Republican | Irvine Lenroot | 11 |
| 8 | Robert M. La Follette | Republican | Jan 4, 1906 – Jun 18, 1925 | Re-elected in 1922.Died. | 14 | 68th | 14 | Re-elected in 1920.Lost renomination. | Apr 18, 1918 – Mar 3, 1927 | Republican | Irvine Lenroot | 11 |
| 8 | Robert M. La Follette | Republican | Jan 4, 1906 – Jun 18, 1925 | Re-elected in 1922.Died. | 14 | 69th | 14 | Re-elected in 1920.Lost renomination. | Apr 18, 1918 – Mar 3, 1927 | Republican | Irvine Lenroot | 11 |
| Vacant | Vacant | Vacant | Jun 18, 1925 – Sep 30, 1925 | | 14 | 69th | 14 | Re-elected in 1920.Lost renomination. | Apr 18, 1918 – Mar 3, 1927 | Republican | Irvine Lenroot | 11 |
| 9 | Robert M. La Follette Jr. | Republican | Sep 30, 1925 – Jan 3, 1947 | Elected to finish his father's term | 14 | 69th | 14 | Re-elected in 1920.Lost renomination. | Apr 18, 1918 – Mar 3, 1927 | Republican | Irvine Lenroot | 11 |
| 9 | Robert M. La Follette Jr. | Republican | Sep 30, 1925 – Jan 3, 1947 | Elected to finish his father's term | 14 | 70th | 15 | Elected in 1926.Lost renomination. | Mar 4, 1927 – Mar 3, 1933 | Republican | John J. Blaine | 12 |
| 9 | Robert M. La Follette Jr. | Republican | Sep 30, 1925 – Jan 3, 1947 | Re-elected in 1928. | 15 | 71st | 15 | Elected in 1926.Lost renomination. | Mar 4, 1927 – Mar 3, 1933 | Republican | John J. Blaine | 12 |
| 9 | Robert M. La Follette Jr. | Republican | Sep 30, 1925 – Jan 3, 1947 | Re-elected in 1928. | 15 | 72nd | 15 | Elected in 1926.Lost renomination. | Mar 4, 1927 – Mar 3, 1933 | Republican | John J. Blaine | 12 |
| 9 | Robert M. La Follette Jr. | Republican | Sep 30, 1925 – Jan 3, 1947 | Re-elected in 1928. | 15 | 73rd | 16 | Elected in 1932.Lost re-election. | Mar 4, 1933 – Jan 3, 1939 | Democratic | F. Ryan Duffy | 13 |
| 9 | Robert M. La Follette Jr. | Progressive | Sep 30, 1925 – Jan 3, 1947 | Re-elected in 1934. | 16 | 74th | 16 | Elected in 1932.Lost re-election. | Mar 4, 1933 – Jan 3, 1939 | Democratic | F. Ryan Duffy | 13 |
| 9 | Robert M. La Follette Jr. | Progressive | Sep 30, 1925 – Jan 3, 1947 | Re-elected in 1934. | 16 | 75th | 16 | Elected in 1932.Lost re-election. | Mar 4, 1933 – Jan 3, 1939 | Democratic | F. Ryan Duffy | 13 |
| 9 | Robert M. La Follette Jr. | Progressive | Sep 30, 1925 – Jan 3, 1947 | Re-elected in 1934. | 16 | 76th | 17 | Elected in 1938. | Jan 3, 1939 – Jan 3, 1963 | Republican | Alexander Wiley | 14 |
| 9 | Robert M. La Follette Jr. | Progressive | Sep 30, 1925 – Jan 3, 1947 | Re-elected in 1940.Lost nomination as a Republican. | 17 | 77th | 17 | Elected in 1938. | Jan 3, 1939 – Jan 3, 1963 | Republican | Alexander Wiley | 14 |
| 9 | Robert M. La Follette Jr. | Progressive | Sep 30, 1925 – Jan 3, 1947 | Re-elected in 1940.Lost nomination as a Republican. | 17 | 78th | 17 | Elected in 1938. | Jan 3, 1939 – Jan 3, 1963 | Republican | Alexander Wiley | 14 |
| 9 | Robert M. La Follette Jr. | Progressive | Sep 30, 1925 – Jan 3, 1947 | Re-elected in 1940.Lost nomination as a Republican. | 17 | 79th | 18 | Re-elected in 1944. | Jan 3, 1939 – Jan 3, 1963 | Republican | Alexander Wiley | 14 |
| 10 | Joseph McCarthy | Republican | Jan 3, 1947 – May 2, 1957 | Elected in 1946. | 18 | 80th | 18 | Re-elected in 1944. | Jan 3, 1939 – Jan 3, 1963 | Republican | Alexander Wiley | 14 |
| 10 | Joseph McCarthy | Republican | Jan 3, 1947 – May 2, 1957 | Elected in 1946. | 18 | 81st | 18 | Re-elected in 1944. | Jan 3, 1939 – Jan 3, 1963 | Republican | Alexander Wiley | 14 |
| 10 | Joseph McCarthy | Republican | Jan 3, 1947 – May 2, 1957 | Elected in 1946. | 18 | 82nd | 19 | Re-elected in 1950. | Jan 3, 1939 – Jan 3, 1963 | Republican | Alexander Wiley | 14 |
| 10 | Joseph McCarthy | Republican | Jan 3, 1947 – May 2, 1957 | Re-elected in 1952.Died. | 19 | 83rd | 19 | Re-elected in 1950. | Jan 3, 1939 – Jan 3, 1963 | Republican | Alexander Wiley | 14 |
| 10 | Joseph McCarthy | Republican | Jan 3, 1947 – May 2, 1957 | Re-elected in 1952.Died. | 19 | 84th | 19 | Re-elected in 1950. | Jan 3, 1939 – Jan 3, 1963 | Republican | Alexander Wiley | 14 |
| 10 | Joseph McCarthy | Republican | Jan 3, 1947 – May 2, 1957 | Re-elected in 1952.Died. | 19 | 85th | 20 | Re-elected in 1956.Lost re-election. | Jan 3, 1939 – Jan 3, 1963 | Republican | Alexander Wiley | 14 |
| Vacant | Vacant | Vacant | May 2, 1957 – Aug 27, 1957 | | 19 | 85th | 20 | Re-elected in 1956.Lost re-election. | Jan 3, 1939 – Jan 3, 1963 | Republican | Alexander Wiley | 14 |
| 11 | William Proxmire | Democratic | Aug 28, 1957 – Jan 3, 1989 | Elected to finish McCarthy's term | 19 | 85th | 20 | Re-elected in 1956.Lost re-election. | Jan 3, 1939 – Jan 3, 1963 | Republican | Alexander Wiley | 14 |
| 11 | William Proxmire | Democratic | Aug 28, 1957 – Jan 3, 1989 | Re-elected in 1958. | 20 | 86th | 20 | Re-elected in 1956.Lost re-election. | Jan 3, 1939 – Jan 3, 1963 | Republican | Alexander Wiley | 14 |
| 11 | William Proxmire | Democratic | Aug 28, 1957 – Jan 3, 1989 | Re-elected in 1958. | 20 | 87th | 20 | Re-elected in 1956.Lost re-election. | Jan 3, 1939 – Jan 3, 1963 | Republican | Alexander Wiley | 14 |
| 11 | William Proxmire | Democratic | Aug 28, 1957 – Jan 3, 1989 | Re-elected in 1958. | 20 | 88th | 21 | Elected in 1962. | Jan 3, 1963 – Jan 3, 1981 | Democratic | Gaylord Nelson | 15 |
| 11 | William Proxmire | Democratic | Aug 28, 1957 – Jan 3, 1989 | Re-elected in 1964. | 21 | 89th | 21 | Elected in 1962. | Jan 3, 1963 – Jan 3, 1981 | Democratic | Gaylord Nelson | 15 |
| 11 | William Proxmire | Democratic | Aug 28, 1957 – Jan 3, 1989 | Re-elected in 1964. | 21 | 90th | 21 | Elected in 1962. | Jan 3, 1963 – Jan 3, 1981 | Democratic | Gaylord Nelson | 15 |
| 11 | William Proxmire | Democratic | Aug 28, 1957 – Jan 3, 1989 | Re-elected in 1964. | 21 | 91st | 22 | Re-elected in 1968. | Jan 3, 1963 – Jan 3, 1981 | Democratic | Gaylord Nelson | 15 |
| 11 | William Proxmire | Democratic | Aug 28, 1957 – Jan 3, 1989 | Re-elected in 1970. | 22 | 92nd | 22 | Re-elected in 1968. | Jan 3, 1963 – Jan 3, 1981 | Democratic | Gaylord Nelson | 15 |
| 11 | William Proxmire | Democratic | Aug 28, 1957 – Jan 3, 1989 | Re-elected in 1970. | 22 | 93rd | 22 | Re-elected in 1968. | Jan 3, 1963 – Jan 3, 1981 | Democratic | Gaylord Nelson | 15 |
| 11 | William Proxmire | Democratic | Aug 28, 1957 – Jan 3, 1989 | Re-elected in 1970. | 22 | 94th | 23 | Re-elected in 1974.Lost re-election. | Jan 3, 1963 – Jan 3, 1981 | Democratic | Gaylord Nelson | 15 |
| 11 | William Proxmire | Democratic | Aug 28, 1957 – Jan 3, 1989 | Re-elected in 1976. | 23 | 95th | 23 | Re-elected in 1974.Lost re-election. | Jan 3, 1963 – Jan 3, 1981 | Democratic | Gaylord Nelson | 15 |
| 11 | William Proxmire | Democratic | Aug 28, 1957 – Jan 3, 1989 | Re-elected in 1976. | 23 | 96th | 23 | Re-elected in 1974.Lost re-election. | Jan 3, 1963 – Jan 3, 1981 | Democratic | Gaylord Nelson | 15 |
| 11 | William Proxmire | Democratic | Aug 28, 1957 – Jan 3, 1989 | Re-elected in 1976. | 23 | 97th | 24 | Elected in 1980. | Jan 3, 1981 – Jan 3, 1993 | Republican | Bob Kasten | 16 |
| 11 | William Proxmire | Democratic | Aug 28, 1957 – Jan 3, 1989 | Re-elected in 1982.Retired. | 24 | 98th | 24 | Elected in 1980. | Jan 3, 1981 – Jan 3, 1993 | Republican | Bob Kasten | 16 |
| 11 | William Proxmire | Democratic | Aug 28, 1957 – Jan 3, 1989 | Re-elected in 1982.Retired. | 24 | 99th | 24 | Elected in 1980. | Jan 3, 1981 – Jan 3, 1993 | Republican | Bob Kasten | 16 |
| 11 | William Proxmire | Democratic | Aug 28, 1957 – Jan 3, 1989 | Re-elected in 1982.Retired. | 24 | 100th | 25 | Re-elected in 1986.Lost re-election. | Jan 3, 1981 – Jan 3, 1993 | Republican | Bob Kasten | 16 |
| 12 | Herb Kohl | Democratic | Jan 3, 1989 – Jan 3, 2013 | Elected in 1988. | 25 | 101st | 25 | Re-elected in 1986.Lost re-election. | Jan 3, 1981 – Jan 3, 1993 | Republican | Bob Kasten | 16 |
| 12 | Herb Kohl | Democratic | Jan 3, 1989 – Jan 3, 2013 | Elected in 1988. | 25 | 102nd | 25 | Re-elected in 1986.Lost re-election. | Jan 3, 1981 – Jan 3, 1993 | Republican | Bob Kasten | 16 |
| 12 | Herb Kohl | Democratic | Jan 3, 1989 – Jan 3, 2013 | Elected in 1988. | 25 | 103rd | 26 | Elected in 1992. | Jan 3, 1993 – Jan 3, 2011 | Democratic | Russ Feingold | 17 |
| 12 | Herb Kohl | Democratic | Jan 3, 1989 – Jan 3, 2013 | Re-elected in 1994. | 26 | 104th | 26 | Elected in 1992. | Jan 3, 1993 – Jan 3, 2011 | Democratic | Russ Feingold | 17 |
| 12 | Herb Kohl | Democratic | Jan 3, 1989 – Jan 3, 2013 | Re-elected in 1994. | 26 | 105th | 26 | Elected in 1992. | Jan 3, 1993 – Jan 3, 2011 | Democratic | Russ Feingold | 17 |
| 12 | Herb Kohl | Democratic | Jan 3, 1989 – Jan 3, 2013 | Re-elected in 1994. | 26 | 106th | 27 | Re-elected in 1998. | Jan 3, 1993 – Jan 3, 2011 | Democratic | Russ Feingold | 17 |
| 12 | Herb Kohl | Democratic | Jan 3, 1989 – Jan 3, 2013 | Re-elected in 2000. | 27 | 107th | 27 | Re-elected in 1998. | Jan 3, 1993 – Jan 3, 2011 | Democratic | Russ Feingold | 17 |
| 12 | Herb Kohl | Democratic | Jan 3, 1989 – Jan 3, 2013 | Re-elected in 2000. | 27 | 108th | 27 | Re-elected in 1998. | Jan 3, 1993 – Jan 3, 2011 | Democratic | Russ Feingold | 17 |
| 12 | Herb Kohl | Democratic | Jan 3, 1989 – Jan 3, 2013 | Re-elected in 2000. | 27 | 109th | 28 | Re-elected in 2004.Lost re-election. | Jan 3, 1993 – Jan 3, 2011 | Democratic | Russ Feingold | 17 |
| 12 | Herb Kohl | Democratic | Jan 3, 1989 – Jan 3, 2013 | Re-elected in 2006.Retired. | 28 | 110th | 28 | Re-elected in 2004.Lost re-election. | Jan 3, 1993 – Jan 3, 2011 | Democratic | Russ Feingold | 17 |
| 12 | Herb Kohl | Democratic | Jan 3, 1989 – Jan 3, 2013 | Re-elected in 2006.Retired. | 28 | 111th | 28 | Re-elected in 2004.Lost re-election. | Jan 3, 1993 – Jan 3, 2011 | Democratic | Russ Feingold | 17 |
| 12 | Herb Kohl | Democratic | Jan 3, 1989 – Jan 3, 2013 | Re-elected in 2006.Retired. | 28 | 112th | 29 | Elected in 2010. | Jan 3, 2011 – present | Republican | Ron Johnson | 18 |
| 13 | Tammy Baldwin | Democratic | Jan 3, 2013 – present | Elected in 2012. | 29 | 113th | 29 | Elected in 2010. | Jan 3, 2011 – present | Republican | Ron Johnson | 18 |
| 13 | Tammy Baldwin | Democratic | Jan 3, 2013 – present | Elected in 2012. | 29 | 114th | 29 | Elected in 2010. | Jan 3, 2011 – present | Republican | Ron Johnson | 18 |
| 13 | Tammy Baldwin | Democratic | Jan 3, 2013 – present | Elected in 2012. | 29 | 115th | 30 | Re-elected in 2016. | Jan 3, 2011 – present | Republican | Ron Johnson | 18 |
| 13 | Tammy Baldwin | Democratic | Jan 3, 2013 – present | Re-elected in 2018. | 30 | 116th | 30 | Re-elected in 2016. | Jan 3, 2011 – present | Republican | Ron Johnson | 18 |
| 13 | Tammy Baldwin | Democratic | Jan 3, 2013 – present | Re-elected in 2018. | 30 | 117th | 30 | Re-elected in 2016. | Jan 3, 2011 – present | Republican | Ron Johnson | 18 |
| 13 | Tammy Baldwin | Democratic | Jan 3, 2013 – present | Re-elected in 2018. | 30 | 118th | 31 | Re-elected in 2022. | Jan 3, 2011 – present | Republican | Ron Johnson | 18 |
| 13 | Tammy Baldwin | Democratic | Jan 3, 2013 – present | Re-elected in 2024. | 31 | 119th | 31 | Re-elected in 2022. | Jan 3, 2011 – present | Republican | Ron Johnson | 18 |
| 13 | Tammy Baldwin | Democratic | Jan 3, 2013 – present | Re-elected in 2024. | 31 | 120th | 31 | Re-elected in 2022. | Jan 3, 2011 – present | Republican | Ron Johnson | 18 |
| 13 | Tammy Baldwin | Democratic | Jan 3, 2013 – present | Re-elected in 2024. | 31 | 121st | 32 | To be determined in the 2028 election. | To be determined in the 2028 election. | To be determined in the 2028 election. | To be determined in the 2028 election. | To be determined in the 2028 election. |
| To be determined in the 2030 election. | To be determined in the 2030 election. | To be determined in the 2030 election. | To be determined in the 2030 election. | To be determined in the 2030 election. | 32 | 122nd | 32 | To be determined in the 2028 election. | To be determined in the 2028 election. | To be determined in the 2028 election. | To be determined in the 2028 election. | To be determined in the 2028 election. |
| # | Senator | Party | Years in office | Electoral history | T | C | T | Electoral history | Years in office | Party | Senator | # |
| Class 1 | Class 1 | Class 1 | Class 1 | Class 1 | Class 1 | C | Class 3 | Class 3 | Class 3 | Class 3 | Class 3 | Class 3 |