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 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.

Current delegation

Jon Tester (D)

Steve Daines (R)

List of senators

#	Senator	Party	Dates in office	Electoral history	T	C	T	Electoral history	Dates in office	Party	Senator	#
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.
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.		51st		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.		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.		53rd
		Republican				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.		56th
Vacant			May 15, 1900 – Mar 7, 1901			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.		57th
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]
						72nd			Mar 2, 1933 – Mar 13, 1933	Vacant
						73rd			Mar 2, 1933 – Mar 13, 1933	Vacant
								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		Elected to finish Walsh's term.^[7]
						75th	9	Re-elected 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. Announced retirement, then resigned to become U.S. Ambassador to China.
						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.					24	119th
To be determined in the 2024 election.					24	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						C	Class 2