List of United States senators from Colorado

Colorado was admitted to the Union on August 1, 1876 and elects U.S. senators to Senate class 2 and class 3.

Current delegation

Both of Colorados current U.S. senators are Democrats Michael Bennet (serving since 2009) and John Hickenlooper (serving since 2021). Colorado is one of fifteen states alongside Arizona, Florida, Georgia, Hawaii, Idaho, Indiana, Louisiana, Maine, Massachusetts, Minnesota, Missouri, Nevada, South Dakota and Utah to have a younger senior senator and an older junior senator.^{[not verified in body]}

Henry M. Teller was Colorado's longest-serving senator (1876–1882; 1885–1909).

List of senators

#	Senator	Party	Dates in office	Electoral history	T	C	T	Electoral history	Dates in office	Party	Senator	#
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.						C	Class 3 Class 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.
Vacant			Aug 1, 1876 – Nov 15, 1876	Colorado did not elect its senators until three months after statehood.	1	44th	1	Colorado did not elect its senators until three months after statehood.	Aug 1, 1876 – Nov 15, 1876	Vacant
1	Henry M. Teller	Republican	Nov 15, 1876 – Apr 17, 1882	Elected in 1876.	1	44th		Elected in 1876. Retired.	Nov 15, 1876 – Mar 3, 1879	Republican	Jerome B. Chaffee	1
				Elected to next term in 1876 or 1877. Resigned to become U.S. Secretary of the Interior.	2	45th		Elected in 1876. Retired.	Nov 15, 1876 – Mar 3, 1879	Republican	Jerome B. Chaffee	1
						46th	2	Elected in 1879. Lost re-nomination.	Mar 4, 1879 – Mar 3, 1885	Republican	Nathaniel P. Hill	2
						47th
2	George M. Chilcott	Republican	Apr 17, 1882 – Jan 27, 1883	Appointed to continue Teller's term. Did not run to finish the term.
3	Horace Tabor	Republican	Jan 27, 1883 – Mar 3, 1883	Elected to finish Teller's term. Retired.
4	Thomas M. Bowen	Republican	Mar 4, 1883 – Mar 3, 1889	Election date unknown. Unknown if retired or lost re-election.	3	48th
						49th	3	Elected in 1885.	Mar 4, 1885 – Mar 3, 1909	Republican	Henry M. Teller	3
						50th
5	Edward O. Wolcott	Republican	Mar 4, 1889 – Mar 3, 1901	Elected in 1889.	4	51st
						52nd	4	Re-elected in 1891.
						53rd
				Re-elected in 1895. Lost re-election.	5	54th
						55th	5	Re-elected in 1897.^[1]		Silver Republican
						56th
6	Thomas M. Patterson	Democratic	Mar 4, 1901 – Mar 3, 1907	Elected in 1901. Retired.	6	57th
						58th	6	Re-elected in 1903. Retired.		Democratic
						59th
7	Simon Guggenheim	Republican	Mar 4, 1907 – Mar 3, 1913	Elected in 1907. Retired.	7	60th
						61st	7	Elected in 1909. Died.	Mar 4, 1909 – Jan 11, 1911	Democratic	Charles J. Hughes Jr.	4
						61st			Jan 11, 1911 – Jan 15, 1913	Vacant
						62nd			Jan 11, 1911 – Jan 15, 1913	Vacant
						62nd		Elected to finish Hughes's term.	Jan 15, 1913 – Mar 3, 1921	Democratic	Charles S. Thomas	5
8	John F. Shafroth	Democratic	Mar 4, 1913 – Mar 3, 1919	Elected in 1913. Lost re-election.	8	63rd		Elected to finish Hughes's term.
						64th	8	Re-elected in 1914. Lost re-election.
						65th
9	Lawrence C. Phipps	Republican	Mar 4, 1919 – Mar 3, 1931	Elected in 1918.	9	66th
						67th	9	Elected in 1920. Died.	Mar 4, 1921 – Mar 24, 1923	Republican	Samuel D. Nicholson	6
						68th		Elected in 1920. Died.	Mar 4, 1921 – Mar 24, 1923	Republican	Samuel D. Nicholson	6
									Mar 24, 1923 – May 17, 1923	Vacant
								Appointed to continue Nicholson's term. Retired.	May 17, 1923 – Nov 30, 1924	Democratic	Alva B. Adams	7
								Elected to finish Nicholson's term. Lost renomination.	Dec 1, 1924 – Mar 3, 1927	Republican	Rice W. Means	8
				Re-elected in 1924. Retired.	10	69th		Elected to finish Nicholson's term. Lost renomination.	Dec 1, 1924 – Mar 3, 1927	Republican	Rice W. Means	8
						70th	10	Elected in 1926. Died.	Mar 4, 1927 – Aug 27, 1932	Republican	Charles W. Waterman	9
						71st
10	Edward P. Costigan	Democratic	Mar 4, 1931 – Jan 3, 1937	Elected in 1930. Retired.	11	72nd
									Aug 27, 1932 – Sep 26, 1932	Vacant
								Appointed to continue Waterman's term. Lost election to finish Waterman's term.	Sep 26, 1932 – Dec 6, 1932	Democratic	Walter Walker	10
								Elected to finish Waterman's term. Lost election to next term.	Dec 7, 1932 – Mar 3, 1933	Republican	Karl C. Schuyler	11
						73rd	11	Elected in 1932.	Mar 4, 1933 – Dec 1, 1941	Democratic	Alva B. Adams	12
						74th
11	Edwin C. Johnson	Democratic	Jan 3, 1937 – Jan 3, 1955	Elected in 1936.	12	75th
						76th	12	Re-elected in 1938. Died.
						77th		Re-elected in 1938. Died.
									Dec 1, 1941 – Dec 20, 1941	Vacant
								Appointed to continue Adams's term. Elected in 1942 to finish Adams's term.^[2]	Dec 20, 1941 – Jan 3, 1957	Republican	Eugene Millikin	13
				Re-elected in 1942.	13	78th
						79th	13	Re-elected in 1944.
						80th
				Re-elected in 1948. Retired to run for Governor.	14	81st
						82nd	14	Re-elected in 1950. Retired
						83rd
12	Gordon Allott	Republican	Jan 3, 1955 – Jan 3, 1973	Elected in 1954.	15	84th
						85th	15	Elected in 1956. Lost re-election.	Jan 3, 1957 – Jan 3, 1963	Democratic	John A. Carroll	14
						86th
				Re-elected in 1960.	16	87th
						88th	16	Elected in 1962.	Jan 3, 1963 – Jan 3, 1975	Republican	Peter H. Dominick	15
						89th
				Re-elected in 1966. Lost re-election.	17	90th
						91st	17	Re-elected in 1968. Lost re-election.
						92nd
13	Floyd Haskell	Democratic	Jan 3, 1973 – Jan 3, 1979	Elected in 1972. Lost re-election.	18	93rd
						94th	18	Elected in 1974.	Jan 3, 1975 – Jan 3, 1987	Democratic	Gary Hart	16
						95th
14	William L. Armstrong	Republican	Jan 3, 1979 – Jan 3, 1991	Elected in 1978.	19	96th
						97th	19	Re-elected in 1980. Retired.
						98th
				Re-elected in 1984. Retired.	20	99th
						100th	20	Elected in 1986. Retired.	Jan 3, 1987 – Jan 3, 1993	Democratic	Tim Wirth	17
						101st
15	Hank Brown	Republican	Jan 3, 1991 – Jan 3, 1997	Elected in 1990. Retired.	21	102nd
						103rd	21	Elected in 1992. Changed parties on March 3, 1995.	Jan 3, 1993 – Jan 3, 2005	Democratic	Ben Nighthorse Campbell	18
						104th				Democratic
						104th				Republican
16	Wayne Allard	Republican	Jan 3, 1997 – Jan 3, 2009	Elected in 1996.	22	105th
						106th	22	Re-elected in 1998. Retired.
						107th
				Re-elected in 2002. Retired.	23	108th
						109th	23	Elected in 2004. Resigned to become U.S. Secretary of the Interior.	Jan 3, 2005 – Jan 20, 2009	Democratic	Ken Salazar	19
						110th
17	Mark Udall	Democratic	Jan 3, 2009 – Jan 3, 2015	Elected in 2008. Lost re-election.	24	111th
						111th		Appointed to finish Salazar's term.	Jan 21, 2009 – present	Democratic	Michael Bennet	20
						112th	24	Elected to a full term in 2010.
						113th
18	Cory Gardner	Republican	Jan 3, 2015 – Jan 3, 2021	Elected in 2014. Lost re-election.	25	114th
						115th	25	Re-elected in 2016.
						116th
19	John Hickenlooper	Democratic	Jan 3, 2021 – present	Elected in 2020.	26	117th
						118th	26	Re-elected in 2022.
						119th
To be determined in the 2026 election.					27	120th
To be determined in the 2026 election.					27	121st	27	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 2						C	Class 3