# List of United States senators from Montana

Montana was admitted to the Union on November 8, 1889, and elects U.S. senators to classes 1 and 2. Its current U.S. senators are Republicans Steve Daines (serving since 2015) and Tim Sheehy (serving since 2025). Democrat Max Baucus is the state's longest serving senator, serving from 1978 to 2014.

## 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 2Class 2 U.S. senators belong to the electoral cycle that has recently been contested in 2002, 2008, 2014, and 2020. The next election will be in 2026. | Class 2Class 2 U.S. senators belong to the electoral cycle that has recently been contested in 2002, 2008, 2014, and 2020. The next election will be in 2026. | Class 2Class 2 U.S. senators belong to the electoral cycle that has recently been contested in 2002, 2008, 2014, and 2020. The next election will be in 2026. | Class 2Class 2 U.S. senators belong to the electoral cycle that has recently been contested in 2002, 2008, 2014, and 2020. The next election will be in 2026. | Class 2Class 2 U.S. senators belong to the electoral cycle that has recently been contested in 2002, 2008, 2014, and 2020. The next election will be in 2026. | Class 2Class 2 U.S. senators belong to the electoral cycle that has recently been contested in 2002, 2008, 2014, and 2020. The next election will be in 2026. |
| # | Senator | Party | Dates in office | Electoral history | T | C | T | Electoral history | Dates in office | Party | Senator | # |
| Vacant | Vacant | Vacant | Nov 8, 1889 – Jan 1, 1890 | Montana elected its first senators two months after admission to the Union. | 1 | 51st | 1 | Montana elected its first senators two months after admission to the Union. | Nov 8, 1889 – Jan 2, 1890 | Vacant | Vacant | Vacant |
| 1 | Wilbur F. Sanders | Republican | Jan 1, 1890 – Mar 3, 1893 | Elected in 1890.Lost re-election. | 1 | 51st | 1 | Elected in 1890.Retired. | Jan 2, 1890 – Mar 3, 1895 | Republican | Thomas C. Power | 1 |
| 1 | Wilbur F. Sanders | Republican | Jan 1, 1890 – Mar 3, 1893 | Elected in 1890.Lost re-election. | 1 | 52nd | 1 | Elected in 1890.Retired. | Jan 2, 1890 – Mar 3, 1895 | Republican | Thomas C. Power | 1 |
| Vacant | Vacant | Vacant | Mar 3, 1893 – Jan 16, 1895 | Legislature failed to elect. | 2 | 53rd | 1 | Elected in 1890.Retired. | Jan 2, 1890 – Mar 3, 1895 | Republican | Thomas C. Power | 1 |
| 2 | Lee Mantle | Republican | Jan 16, 1895 – Mar 3, 1899 | Elected to finish vacant term.Lost renomination. | 2 | 53rd | 1 | Elected in 1890.Retired. | Jan 2, 1890 – Mar 3, 1895 | Republican | Thomas C. Power | 1 |
| 2 | Lee Mantle | Republican | Jan 16, 1895 – Mar 3, 1899 | Elected to finish vacant term.Lost renomination. | 2 | 54th | 2 | Elected in Jan 1895.Lost re-election. | Mar 4, 1895 – Mar 3, 1901 | Republican | Thomas H. Carter | 2 |
| 2 | Lee Mantle | Silver Republican | Jan 16, 1895 – Mar 3, 1899 | Elected to finish vacant term.Lost renomination. | 2 | 55th | 2 | Elected in Jan 1895.Lost re-election. | Mar 4, 1895 – Mar 3, 1901 | Republican | Thomas H. Carter | 2 |
| 3 | William Clark | Democratic | Mar 4, 1899 – May 15, 1900 | Elected in 1899.Resigned to avoid claim of election fraud. | 3 | 56th | 2 | Elected in Jan 1895.Lost re-election. | Mar 4, 1895 – Mar 3, 1901 | Republican | Thomas H. Carter | 2 |
| Vacant | Vacant | Vacant | May 15, 1900 – Mar 7, 1901 | Clark was appointed to continue his term, but did not qualify. | 3 | 56th | 2 | Elected in Jan 1895.Lost re-election. | Mar 4, 1895 – Mar 3, 1901 | Republican | Thomas H. Carter | 2 |
| Vacant | Vacant | Vacant | May 15, 1900 – Mar 7, 1901 | Clark was appointed to continue his term, but did not qualify. | 3 | 57th | 3 | Elected in 1901.Retired. | Mar 4, 1901 – Mar 3, 1907 | Democratic | William Clark | 3 |
| 4 | Paris Gibson | Democratic | Mar 7, 1901 – Mar 3, 1905 | Elected to finish Clark's term.Retired. | 3 | 57th | 3 | Elected in 1901.Retired. | Mar 4, 1901 – Mar 3, 1907 | Democratic | William Clark | 3 |
| 4 | Paris Gibson | Democratic | Mar 7, 1901 – Mar 3, 1905 | Elected to finish Clark's term.Retired. | 3 | 58th | 3 | Elected in 1901.Retired. | Mar 4, 1901 – Mar 3, 1907 | Democratic | William Clark | 3 |
| 5 | Thomas H. Carter | Republican | Mar 4, 1905 – Mar 3, 1911 | Elected Jan 16, 1905.Lost re-election. | 4 | 59th | 3 | Elected in 1901.Retired. | Mar 4, 1901 – Mar 3, 1907 | Democratic | William Clark | 3 |
| 5 | Thomas H. Carter | Republican | Mar 4, 1905 – Mar 3, 1911 | Elected Jan 16, 1905.Lost re-election. | 4 | 60th | 4 | Elected Jan 16, 1907.Lost re-election as a Progressive. | Mar 4, 1907 – Mar 3, 1913 | Republican | Joseph M. Dixon | 4 |
| 5 | Thomas H. Carter | Republican | Mar 4, 1905 – Mar 3, 1911 | Elected Jan 16, 1905.Lost re-election. | 4 | 61st | 4 | Elected Jan 16, 1907.Lost re-election as a Progressive. | Mar 4, 1907 – Mar 3, 1913 | Republican | Joseph M. Dixon | 4 |
| 6 | Henry L. Myers | Democratic | Mar 4, 1911 – Mar 3, 1923 | Elected Mar 2, 1911. | 5 | 62nd | 4 | Elected Jan 16, 1907.Lost re-election as a Progressive. | Mar 4, 1907 – Mar 3, 1913 | Republican | Joseph M. Dixon | 4 |
| 6 | Henry L. Myers | Democratic | Mar 4, 1911 – Mar 3, 1923 | Elected Mar 2, 1911. | 5 | 63rd | 5 | Elected Jan 14, 1913. | Mar 4, 1913 – Mar 2, 1933 | Democratic | Thomas J. Walsh | 5 |
| 6 | Henry L. Myers | Democratic | Mar 4, 1911 – Mar 3, 1923 | Elected Mar 2, 1911. | 5 | 64th | 5 | Elected Jan 14, 1913. | Mar 4, 1913 – Mar 2, 1933 | Democratic | Thomas J. Walsh | 5 |
| 6 | Henry L. Myers | Democratic | Mar 4, 1911 – Mar 3, 1923 | Re-elected in 1916.Retired. | 6 | 65th | 5 | Elected Jan 14, 1913. | Mar 4, 1913 – Mar 2, 1933 | Democratic | Thomas J. Walsh | 5 |
| 6 | Henry L. Myers | Democratic | Mar 4, 1911 – Mar 3, 1923 | Re-elected in 1916.Retired. | 6 | 66th | 6 | Re-elected in 1918. | Mar 4, 1913 – Mar 2, 1933 | Democratic | Thomas J. Walsh | 5 |
| 6 | Henry L. Myers | Democratic | Mar 4, 1911 – Mar 3, 1923 | Re-elected in 1916.Retired. | 6 | 67th | 6 | Re-elected in 1918. | Mar 4, 1913 – Mar 2, 1933 | Democratic | Thomas J. Walsh | 5 |
| 7 | Burton K. Wheeler | Democratic | Mar 4, 1923 – Jan 3, 1947 | Elected in 1922. | 7 | 68th | 6 | Re-elected in 1918. | Mar 4, 1913 – Mar 2, 1933 | Democratic | Thomas J. Walsh | 5 |
| 7 | Burton K. Wheeler | Democratic | Mar 4, 1923 – Jan 3, 1947 | Elected in 1922. | 7 | 69th | 7 | Re-elected in 1924. | Mar 4, 1913 – Mar 2, 1933 | Democratic | Thomas J. Walsh | 5 |
| 7 | Burton K. Wheeler | Democratic | Mar 4, 1923 – Jan 3, 1947 | Elected in 1922. | 7 | 70th | 7 | Re-elected in 1924. | Mar 4, 1913 – Mar 2, 1933 | Democratic | Thomas J. Walsh | 5 |
| 7 | Burton K. Wheeler | Democratic | Mar 4, 1923 – Jan 3, 1947 | Re-elected in 1928. | 8 | 71st | 7 | Re-elected in 1924. | Mar 4, 1913 – Mar 2, 1933 | Democratic | Thomas J. Walsh | 5 |
| 7 | Burton K. Wheeler | Democratic | Mar 4, 1923 – Jan 3, 1947 | Re-elected in 1928. | 8 | 72nd | 8 | Re-elected in 1930.Died. | Mar 4, 1913 – Mar 2, 1933 | Democratic | Thomas J. Walsh | 5 |
| 7 | Burton K. Wheeler | Democratic | Mar 4, 1923 – Jan 3, 1947 | Re-elected in 1928. | 8 | 72nd | 8 | | Mar 2, 1933 – Mar 13, 1933 | Vacant | Vacant | Vacant |
| 7 | Burton K. Wheeler | Democratic | Mar 4, 1923 – Jan 3, 1947 | Re-elected in 1928. | 8 | 73rd | 8 | | Mar 2, 1933 – Mar 13, 1933 | Vacant | Vacant | Vacant |
| 7 | Burton K. Wheeler | Democratic | Mar 4, 1923 – Jan 3, 1947 | Re-elected in 1928. | 8 | 73rd | 8 | Appointed to continue Walsh's term.Lost nomination to finish Walsh's term. | Mar 13, 1933 – Nov 6, 1934 | Democratic | John E. Erickson | 6 |
| 7 | Burton K. Wheeler | Democratic | Mar 4, 1923 – Jan 3, 1947 | Re-elected in 1928. | 8 | 73rd | 8 | Elected to finish Walsh's term. | Nov 7, 1934 – Jan 3, 1961 | Democratic | James E. Murray | 7 |
| 7 | Burton K. Wheeler | Democratic | Mar 4, 1923 – Jan 3, 1947 | Re-elected in 1934. | 9 | 74th | 8 | Elected to finish Walsh's term. | Nov 7, 1934 – Jan 3, 1961 | Democratic | James E. Murray | 7 |
| 7 | Burton K. Wheeler | Democratic | Mar 4, 1923 – Jan 3, 1947 | Re-elected in 1934. | 9 | 75th | 9 | Re-elected in 1936. | Nov 7, 1934 – Jan 3, 1961 | Democratic | James E. Murray | 7 |
| 7 | Burton K. Wheeler | Democratic | Mar 4, 1923 – Jan 3, 1947 | Re-elected in 1934. | 9 | 76th | 9 | Re-elected in 1936. | Nov 7, 1934 – Jan 3, 1961 | Democratic | James E. Murray | 7 |
| 7 | Burton K. Wheeler | Democratic | Mar 4, 1923 – Jan 3, 1947 | Re-elected in 1940.Lost renomination. | 10 | 77th | 9 | Re-elected in 1936. | Nov 7, 1934 – Jan 3, 1961 | Democratic | James E. Murray | 7 |
| 7 | Burton K. Wheeler | Democratic | Mar 4, 1923 – Jan 3, 1947 | Re-elected in 1940.Lost renomination. | 10 | 78th | 10 | Re-elected in 1942. | Nov 7, 1934 – Jan 3, 1961 | Democratic | James E. Murray | 7 |
| 7 | Burton K. Wheeler | Democratic | Mar 4, 1923 – Jan 3, 1947 | Re-elected in 1940.Lost renomination. | 10 | 79th | 10 | Re-elected in 1942. | Nov 7, 1934 – Jan 3, 1961 | Democratic | James E. Murray | 7 |
| 8 | Zales Ecton | Republican | Jan 3, 1947 – Jan 3, 1953 | Elected in 1946.Lost re-election. | 11 | 80th | 10 | Re-elected in 1942. | Nov 7, 1934 – Jan 3, 1961 | Democratic | James E. Murray | 7 |
| 8 | Zales Ecton | Republican | Jan 3, 1947 – Jan 3, 1953 | Elected in 1946.Lost re-election. | 11 | 81st | 11 | Re-elected in 1948. | Nov 7, 1934 – Jan 3, 1961 | Democratic | James E. Murray | 7 |
| 8 | Zales Ecton | Republican | Jan 3, 1947 – Jan 3, 1953 | Elected in 1946.Lost re-election. | 11 | 82nd | 11 | Re-elected in 1948. | Nov 7, 1934 – Jan 3, 1961 | Democratic | James E. Murray | 7 |
| 9 | Mike Mansfield | Democratic | Jan 3, 1953 – Jan 3, 1977 | Elected in 1952. | 12 | 83rd | 11 | Re-elected in 1948. | Nov 7, 1934 – Jan 3, 1961 | Democratic | James E. Murray | 7 |
| 9 | Mike Mansfield | Democratic | Jan 3, 1953 – Jan 3, 1977 | Elected in 1952. | 12 | 84th | 12 | Re-elected in 1954.Retired. | Nov 7, 1934 – Jan 3, 1961 | Democratic | James E. Murray | 7 |
| 9 | Mike Mansfield | Democratic | Jan 3, 1953 – Jan 3, 1977 | Elected in 1952. | 12 | 85th | 12 | Re-elected in 1954.Retired. | Nov 7, 1934 – Jan 3, 1961 | Democratic | James E. Murray | 7 |
| 9 | Mike Mansfield | Democratic | Jan 3, 1953 – Jan 3, 1977 | Re-elected in 1958. | 13 | 86th | 12 | Re-elected in 1954.Retired. | Nov 7, 1934 – Jan 3, 1961 | Democratic | James E. Murray | 7 |
| 9 | Mike Mansfield | Democratic | Jan 3, 1953 – Jan 3, 1977 | Re-elected in 1958. | 13 | 87th | 13 | Elected in 1960. | Jan 3, 1961 – Jan 12, 1978 | Democratic | Lee Metcalf | 8 |
| 9 | Mike Mansfield | Democratic | Jan 3, 1953 – Jan 3, 1977 | Re-elected in 1958. | 13 | 88th | 13 | Elected in 1960. | Jan 3, 1961 – Jan 12, 1978 | Democratic | Lee Metcalf | 8 |
| 9 | Mike Mansfield | Democratic | Jan 3, 1953 – Jan 3, 1977 | Re-elected in 1964. | 14 | 89th | 13 | Elected in 1960. | Jan 3, 1961 – Jan 12, 1978 | Democratic | Lee Metcalf | 8 |
| 9 | Mike Mansfield | Democratic | Jan 3, 1953 – Jan 3, 1977 | Re-elected in 1964. | 14 | 90th | 14 | Re-elected in 1966. | Jan 3, 1961 – Jan 12, 1978 | Democratic | Lee Metcalf | 8 |
| 9 | Mike Mansfield | Democratic | Jan 3, 1953 – Jan 3, 1977 | Re-elected in 1964. | 14 | 91st | 14 | Re-elected in 1966. | Jan 3, 1961 – Jan 12, 1978 | Democratic | Lee Metcalf | 8 |
| 9 | Mike Mansfield | Democratic | Jan 3, 1953 – Jan 3, 1977 | Re-elected in 1970.Retired. | 15 | 92nd | 14 | Re-elected in 1966. | Jan 3, 1961 – Jan 12, 1978 | Democratic | Lee Metcalf | 8 |
| 9 | Mike Mansfield | Democratic | Jan 3, 1953 – Jan 3, 1977 | Re-elected in 1970.Retired. | 15 | 93rd | 15 | Re-elected in 1972.Died. | Jan 3, 1961 – Jan 12, 1978 | Democratic | Lee Metcalf | 8 |
| 9 | Mike Mansfield | Democratic | Jan 3, 1953 – Jan 3, 1977 | Re-elected in 1970.Retired. | 15 | 94th | 15 | Re-elected in 1972.Died. | Jan 3, 1961 – Jan 12, 1978 | Democratic | Lee Metcalf | 8 |
| 10 | John Melcher | Democratic | Jan 3, 1977 – Jan 3, 1989 | Elected in 1976. | 16 | 95th | 15 | Re-elected in 1972.Died. | Jan 3, 1961 – Jan 12, 1978 | Democratic | Lee Metcalf | 8 |
| 10 | John Melcher | Democratic | Jan 3, 1977 – Jan 3, 1989 | Elected in 1976. | 16 | 95th | 15 | | Jan 12, 1978 – Jan 22, 1978 | Vacant | Vacant | Vacant |
| 10 | John Melcher | Democratic | Jan 3, 1977 – Jan 3, 1989 | Elected in 1976. | 16 | 95th | 15 | Appointed to finish Metcalf's term.Lost nomination to full term.Resigned early to give successor preferential seniority. | Jan 22, 1978 – Dec 14, 1978 | Democratic | Paul G. Hatfield | 9 |
| 10 | John Melcher | Democratic | Jan 3, 1977 – Jan 3, 1989 | Elected in 1976. | 16 | 95th | 15 | | Dec 14, 1978 – Dec 15, 1978 | Vacant | Vacant | Vacant |
| 10 | John Melcher | Democratic | Jan 3, 1977 – Jan 3, 1989 | Elected in 1976. | 16 | 95th | 15 | Appointed early to finish Metcalf's term, having already been elected to the next term. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 10 | John Melcher | Democratic | Jan 3, 1977 – Jan 3, 1989 | Elected in 1976. | 16 | 96th | 16 | Elected in 1978. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 10 | John Melcher | Democratic | Jan 3, 1977 – Jan 3, 1989 | Elected in 1976. | 16 | 97th | 16 | Elected in 1978. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 10 | John Melcher | Democratic | Jan 3, 1977 – Jan 3, 1989 | Re-elected in 1982.Lost re-election. | 17 | 98th | 16 | Elected in 1978. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 10 | John Melcher | Democratic | Jan 3, 1977 – Jan 3, 1989 | Re-elected in 1982.Lost re-election. | 17 | 99th | 17 | Re-elected in 1984. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 10 | John Melcher | Democratic | Jan 3, 1977 – Jan 3, 1989 | Re-elected in 1982.Lost re-election. | 17 | 100th | 17 | Re-elected in 1984. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 11 | Conrad Burns | Republican | Jan 3, 1989 – Jan 3, 2007 | Elected in 1988. | 18 | 101st | 17 | Re-elected in 1984. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 11 | Conrad Burns | Republican | Jan 3, 1989 – Jan 3, 2007 | Elected in 1988. | 18 | 102nd | 18 | Re-elected in 1990. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 11 | Conrad Burns | Republican | Jan 3, 1989 – Jan 3, 2007 | Elected in 1988. | 18 | 103rd | 18 | Re-elected in 1990. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 11 | Conrad Burns | Republican | Jan 3, 1989 – Jan 3, 2007 | Re-elected in 1994. | 19 | 104th | 18 | Re-elected in 1990. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 11 | Conrad Burns | Republican | Jan 3, 1989 – Jan 3, 2007 | Re-elected in 1994. | 19 | 105th | 19 | Re-elected in 1996. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 11 | Conrad Burns | Republican | Jan 3, 1989 – Jan 3, 2007 | Re-elected in 1994. | 19 | 106th | 19 | Re-elected in 1996. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 11 | Conrad Burns | Republican | Jan 3, 1989 – Jan 3, 2007 | Re-elected in 2000.Lost re-election. | 20 | 107th | 19 | Re-elected in 1996. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 11 | Conrad Burns | Republican | Jan 3, 1989 – Jan 3, 2007 | Re-elected in 2000.Lost re-election. | 20 | 108th | 20 | Re-elected in 2002. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 11 | Conrad Burns | Republican | Jan 3, 1989 – Jan 3, 2007 | Re-elected in 2000.Lost re-election. | 20 | 109th | 20 | Re-elected in 2002. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 12 | Jon Tester | Democratic | Jan 3, 2007 – Jan 3, 2025 | Elected in 2006. | 21 | 110th | 20 | Re-elected in 2002. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 12 | Jon Tester | Democratic | Jan 3, 2007 – Jan 3, 2025 | Elected in 2006. | 21 | 111th | 21 | Re-elected in 2008.Announced retirement, then resigned to become U.S. Ambassador to China. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 12 | Jon Tester | Democratic | Jan 3, 2007 – Jan 3, 2025 | Elected in 2006. | 21 | 112th | 21 | Re-elected in 2008.Announced retirement, then resigned to become U.S. Ambassador to China. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 12 | Jon Tester | Democratic | Jan 3, 2007 – Jan 3, 2025 | Re-elected in 2012. | 22 | 113th | 21 | Re-elected in 2008.Announced retirement, then resigned to become U.S. Ambassador to China. | Dec 15, 1978 – Feb 6, 2014 | Democratic | Max Baucus | 10 |
| 12 | Jon Tester | Democratic | Jan 3, 2007 – Jan 3, 2025 | Re-elected in 2012. | 22 | 113th | 21 | | Feb 6, 2014 – Feb 9, 2014 | Vacant | Vacant | Vacant |
| 12 | Jon Tester | Democratic | Jan 3, 2007 – Jan 3, 2025 | Re-elected in 2012. | 22 | 113th | 21 | Appointed to finish Baucus's term.Ran for election to full term, but withdrew. | Feb 9, 2014 – Jan 3, 2015 | Democratic | John Walsh | 11 |
| 12 | Jon Tester | Democratic | Jan 3, 2007 – Jan 3, 2025 | Re-elected in 2012. | 22 | 114th | 22 | Elected in 2014. | Jan 3, 2015 – present | Republican | Steve Daines | 12 |
| 12 | Jon Tester | Democratic | Jan 3, 2007 – Jan 3, 2025 | Re-elected in 2012. | 22 | 115th | 22 | Elected in 2014. | Jan 3, 2015 – present | Republican | Steve Daines | 12 |
| 12 | Jon Tester | Democratic | Jan 3, 2007 – Jan 3, 2025 | Re-elected in 2018.Lost re-election. | 23 | 116th | 22 | Elected in 2014. | Jan 3, 2015 – present | Republican | Steve Daines | 12 |
| 12 | Jon Tester | Democratic | Jan 3, 2007 – Jan 3, 2025 | Re-elected in 2018.Lost re-election. | 23 | 117th | 23 | Re-elected in 2020. | Jan 3, 2015 – present | Republican | Steve Daines | 12 |
| 12 | Jon Tester | Democratic | Jan 3, 2007 – Jan 3, 2025 | Re-elected in 2018.Lost re-election. | 23 | 118th | 23 | Re-elected in 2020. | Jan 3, 2015 – present | Republican | Steve Daines | 12 |
| 13 | Tim Sheehy | Republican | Jan 3, 2025 – present | Elected in 2024. | 24 | 119th | 23 | Re-elected in 2020. | Jan 3, 2015 – present | Republican | Steve Daines | 12 |
| 13 | Tim Sheehy | Republican | Jan 3, 2025 – present | Elected in 2024. | 24 | 120th | 24 | To be determined in the 2026 election. | To be determined in the 2026 election. | To be determined in the 2026 election. | To be determined in the 2026 election. | To be determined in the 2026 election. |
| 13 | Tim Sheehy | Republican | Jan 3, 2025 – present | Elected in 2024. | 24 | 121st | 24 | To be determined in the 2026 election. | To be determined in the 2026 election. | To be determined in the 2026 election. | To be determined in the 2026 election. | To be determined in the 2026 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. | 25 | 122nd | 24 | To be determined in the 2026 election. | To be determined in the 2026 election. | To be determined in the 2026 election. | To be determined in the 2026 election. | To be determined in the 2026 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 2 | Class 2 | Class 2 | Class 2 | Class 2 | Class 2 |