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 Democrat Jon Tester (serving since 2007) and Republican Steve Daines (serving since 2015), making it one of five states to have a United States Senate delegation split between Republican and Democratic caucusing senators. Max Baucus is the state's longest serving senator, serving from 1978 to 2014.
Class 1 Class 1 U.S. senators belong to the electoral cycle that has recently been contested in 2000, 2006, 2012, and 2018. The next election will be in 2024. | C | Class 2 Class 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 | T | Electoral history | Dates in office | Party | Senator | # | |
| 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 | ||||
| 1 |  Wilbur F. Sanders | Republican | Jan 1, 1890 – Mar 3, 1893 | Elected in 1890.Lost re-election. | Elected in 1890.Retired. | Jan 2, 1890 – Mar 3, 1895 | Republican |  Thomas C. Power | 1 | |||
| 52nd | ||||||||||||
| Vacant | Mar 3, 1893 – Jan 16, 1895 | Legislature failed to elect. | 2 | 53rd | ||||||||
| 2 |  Lee Mantle | Republican | Jan 16, 1895 – Mar 3, 1899 | Elected to finish vacant term.Lost renomination. | ||||||||
| 54th | 2 | Elected in Jan 1895. [1] Lost re-election. | Mar 4, 1895 – Mar 3, 1901 | Republican |  Thomas H. Carter | 2 | ||||||
| Silver Republican | 55th | |||||||||||
| 3 |  William Clark | Democratic | Mar 4, 1899 – May 15, 1900 | Elected in 1899.Resigned to avoid claim of election fraud. | 3 | 56th | ||||||
| Vacant | May 15, 1900 – Mar 7, 1901 | Clark was appointed to continue his term, but did not qualify. | ||||||||||
| 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. [2] [3] Retired. | ||||||||
| 58th | ||||||||||||
| 5 |  Thomas H. Carter | Republican | Mar 4, 1905 – Mar 3, 1911 | Elected Jan 16, 1905. [4] Lost re-election. | 4 | 59th | ||||||
| 60th | 4 | Elected Jan 16, 1907. [5] Lost re-election as a Progressive. | Mar 4, 1907 – Mar 3, 1913 | Republican |  Joseph M. Dixon | 4 | ||||||
| 61st | ||||||||||||
| 6 |  Henry L. Myers | Democratic | Mar 4, 1911 – Mar 3, 1923 | Elected Mar 2, 1911. | 5 | 62nd | ||||||
| 63rd | 5 | Elected Jan 14, 1913. | Mar 4, 1913 – Mar 2, 1933 | Democratic |  Thomas J. Walsh | 5 | ||||||
| 64th | ||||||||||||
| Re-elected in 1916.Retired. | 6 | 65th | ||||||||||
| 66th | 6 | Re-elected in 1918. | ||||||||||
| 67th | ||||||||||||
| 7 |  Burton K. Wheeler | Democratic | Mar 4, 1923 – Jan 3, 1947 | Elected in 1922. | 7 | 68th | ||||||
| 69th | 7 | Re-elected in 1924. | ||||||||||
| 70th | ||||||||||||
| Re-elected in 1928. | 8 | 71st | ||||||||||
| 72nd | 8 | Re-elected in 1930.Died. [6] | ||||||||||
| Mar 2, 1933 – Mar 13, 1933 | Vacant | |||||||||||
| 73rd | ||||||||||||
| Appointed to continue Walsh's term.Lost nomination to finish Walsh's term. | Mar 13, 1933 – Nov 6, 1934 | Democratic |  John E. Erickson | 6 | ||||||||
| Elected to finish Walsh's term. [7] | Nov 7, 1934 – Jan 3, 1961 | Democratic |  James E. Murray | 7 | ||||||||
| Re-elected in 1934. | 9 | 74th | ||||||||||
| 75th | 9 | Elected to full term in 1936. | ||||||||||
| 76th | ||||||||||||
| Re-elected in 1940.Lost renomination. | 10 | 77th | ||||||||||
| 78th | 10 | Re-elected in 1942. | ||||||||||
| 79th | ||||||||||||
| 8 |  Zales Ecton | Republican | Jan 3, 1947 – Jan 3, 1953 | Elected in 1946.Lost re-election. | 11 | 80th | ||||||
| 81st | 11 | Re-elected in 1948. | ||||||||||
| 82nd | ||||||||||||
| 9 |  Mike Mansfield | Democratic | Jan 3, 1953 – Jan 3, 1977 | Elected in 1952. [8] | 12 | 83rd | ||||||
| 84th | 12 | Re-elected in 1954.Retired. | ||||||||||
| 85th | ||||||||||||
| Re-elected in 1958. | 13 | 86th | ||||||||||
| 87th | 13 | Elected in 1960. [9] | Jan 3, 1961 – Jan 12, 1978 | Democratic |  Lee Metcalf | 8 | ||||||
| 88th | ||||||||||||
| Re-elected in 1964. | 14 | 89th | ||||||||||
| 90th | 14 | Re-elected in 1966. | ||||||||||
| 91st | ||||||||||||
| Re-elected in 1970.Retired. | 15 | 92nd | ||||||||||
| 93rd | 15 | Re-elected in 1972.Died. | ||||||||||
| 94th | ||||||||||||
| 10 |  John Melcher | Democratic | Jan 3, 1977 – Jan 3, 1989 | Elected in 1976. | 16 | 95th | ||||||
| Jan 12, 1978 – Jan 22, 1978 | Vacant | |||||||||||
| 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 | ||||||||
| Dec 14, 1978 – Dec 15, 1978 | Vacant | |||||||||||
| Appointed early to finish Metcalf's term, having already been elected to the next term. [10] | Dec 15, 1978 – Feb 6, 2014 | Democratic |  Max Baucus | 10 | ||||||||
| 96th | 16 | Elected in 1978. | ||||||||||
| 97th | ||||||||||||
| Re-elected in 1982.Lost re-election. | 17 | 98th | ||||||||||
| 99th | 17 | Re-elected in 1984. | ||||||||||
| 100th | ||||||||||||
| 11 |  Conrad Burns | Republican | Jan 3, 1989 – Jan 3, 2007 | Elected in 1988. | 18 | 101st | ||||||
| 102nd | 18 | Re-elected in 1990. | ||||||||||
| 103rd | ||||||||||||
| Re-elected in 1994. | 19 | 104th | ||||||||||
| 105th | 19 | Re-elected in 1996. | ||||||||||
| 106th | ||||||||||||
| Re-elected in 2000.Lost re-election. | 20 | 107th | ||||||||||
| 108th | 20 | Re-elected in 2002. | ||||||||||
| 109th | ||||||||||||
| 12 |  Jon Tester | Democratic | Jan 3, 2007 – present | Elected in 2006. | 21 | 110th | ||||||
| 111th | 21 | Re-elected in 2008.Resigned to become U.S. Ambassador to China, having already planned to retire at the end of term. | ||||||||||
| 112th | ||||||||||||
| Re-elected in 2012. | 22 | 113th | ||||||||||
| Feb 6, 2014 – Feb 9, 2014 | Vacant | |||||||||||
| Appointed to finish Baucus's term.Ran for election to full term, but withdrew. | Feb 9, 2014 – Jan 3, 2015 | Democratic |  John Walsh | 11 | ||||||||
| 114th | 22 | Elected in 2014. | Jan 3, 2015 – present | Republican |  Steve Daines | 12 | ||||||
| 115th | ||||||||||||
| Re-elected in 2018. | 23 | 116th | ||||||||||
| 117th | 23 | Re-elected in 2020. | ||||||||||
| 118th | ||||||||||||
| To be determined in the 2024 election. | 23 | 119th | ||||||||||
| 120th | 24 | 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 2 | |||||||||||
Maxwell Sieben Baucus is an American politician who served as a United States senator from Montana from 1978 to 2014. A member of the Democratic Party, he was a U.S. senator for over 35 years, making him the longest-serving U.S. senator in Montana history. President Barack Obama appointed Baucus to replace Gary Locke as the 11th U.S. Ambassador to the People's Republic of China, a position he held from 2014 until 2017.
Since Montana became a U.S. state in 1889, it has sent congressional delegations to the United States Senate and the United States House of Representatives. Each state elects two senators to serve for six years. Before the Seventeenth Amendment took effect in 1913, senators were elected by the Montana State Legislature. Members of the House of Representatives are elected to two-year terms, one from Montana's at-large congressional district. Before becoming a state, the Territory of Montana elected a non-voting delegate at-large to Congress from 1864 to 1889.
Thomas James Walsh was an American lawyer and Democratic Party politician from Helena, Montana who represented Montana in the US Senate from 1913 to 1933. He was initially elected by the state legislature, and from 1918 on by popular vote, in keeping with the requirements of the Seventeenth Amendment to the United States Constitution.
Joseph Kemp Toole was a Democratic politician from Montana. He served as the first and fourth Governor of Montana.
The 2008 United States Senate election in Montana was held on November 4, 2008. Incumbent Democratic Senator Max Baucus won re-election to a sixth term in a landslide, winning more than 70% of the vote and carrying every county in the state, despite Republican John McCain's narrow victory in the state in the concurrent presidential election. Baucus was later appointed as the United States Ambassador to China on February 6, 2014, having already announced his intention to retire at the end of term on April 23, 2013.
Steven David Daines is an American politician and former corporate executive serving as the junior United States senator from Montana since 2015. A member of the Republican Party, he represented Montana's at-large congressional district in the U.S. House of Representatives from 2013 to 2015.
Donald W. Molloy is a senior United States district judge of the United States District Court for the District of Montana.
Corey Stapleton is an American politician and musician who served as the Secretary of State of Montana from 2017 to 2021. A Republican, he served as a member of the Montana State Senate from 2001 to 2009.
John Edward Walsh is an American real estate agent, former politician and former military officer who served as a United States Senator from Montana from 2014 to 2015. A member of the Democratic Party, he previously served as a colonel in the Army National Guard, the adjutant general of the Montana National Guard with a state commission as a brigadier general from 2008 to 2012 and the 34th Lieutenant Governor of Montana from 2013 to 2014 under Governor Steve Bullock.
The 2014 congressional election in Montana was held on November 4, 2014, to elect the U.S. representative from Montana's at-large congressional district. Between 1993 and 2023, Montana had one at-large seat in the House.
| Class 1 |  | |
|---|---|---|
| Class 2 | ||
