U.S. Senate elections in Colorado
Elections won
R 20 · D 1939 Senate elections since 1914
Last decided by
14.6 pts2022, Michael F. Bennet over Joe O'Dea
Closest ever
0.44 pts1956, John A. Carroll over Daniel I. J. Thornton
Longest streak
5 in a rowRepublican, 1918–1926
Next election
2026Tuesday, November 3, 2026
Colorado's U.S. Senate seats are held by Democrat Michael F. Bennet and Democrat John W. Hickenlooper; Bennet won the most recent race by 14.6 points in 2022. Bennet has held one seat since 2010 and Hickenlooper the other since 2020. The 2022 race put Bennet ahead of Joe O'Dea, 14.6 points clear. Across 39 elections since 1914, Republicans have won 20 and Democrats 19. Of those, the closest was 1956, decided by 0.44 points; the widest 1948, by 34.4 points.
Michael F. Bennet D 1,397,170 · Joe O'Dea R 1,031,693 · Brian Peotter L 43,534 · T.j. Cole U 16,379 · +5 more
John W. Hickenlooper D 1,731,114 · Cory Gardner R 1,429,492 · Raymon Anthony Doane L 56,262 · Daniel Doyle A 9,820 · +4 more
Michael F. Bennet D 1,370,710 · Darryl Glenn R 1,215,318 · Lily Tang Williams L 99,277 · Arn Menconi G 36,805 · +3 more
Cory Gardner R 983,891 · Mark Udall D 944,203 · Gaylon Kent L 52,876 · Steve Shogan U 29,472 · +2 more
Michael F. Bennet D 851,590 · Ken Buck R 822,731 · Bob Kinsey G 38,768 · MacLyn Mac Stringer L 22,589 · +3 more
Mark Udall D 1,230,994 · Bob Schaffer R 990,755 · Douglas Dayhorse Campbell A 59,733 · Bob Kinsey G 50,004
Ken Salazar D 1,081,188 · Pete Coors R 980,668 · Douglas Dayhorse Campbell A 18,783 · Richard Randall L 10,160 · +3 more
Wayne Allard R 717,893 · Tom Strickland D 648,130 · Doulgas Dayhorse Campbell A 21,547 · Rick Stanley L 20,776 · +1 more
Ben Nighthorse Campbell R 829,370 · Dottie Lamm D 464,754 · David S. Segal L 14,024 · Kevin Swanson A 9,775 · +3 more
Ben Nighthorse Campbell D 803,725 · Terry Considine R 662,893 · Richard O. Grimes P 42,455 · Matt Noah C 22,846 · +2 more
Timothy E. Wirth D 529,449 · Ken Kramer R 512,994 · Michael Martin Bush I 11,127 · Michael R. Chamberlain S 3,756 · +2 more
William L. Bill Armstrong R 833,821 · Nancy Dick D 449,327 · Craig Green L 11,077 · David Martin S 2,208 · +1 more
Gary Hart D 590,501 · Mary Estill Buchanan R 571,295 · Earl Higgerson S 7,265 · Henry John Olshaw U 4,081
William L. Bill Armstrong R 480,801 · Floyd K. Haskell D 330,148 · Vedder V Dron U 5,789 · John Shue N 2,518
Gary Hart D 471,691 · Peter H. Dominick R 325,508 · John M. King I 16,131 · Fred Hyskell P 8,410 · +1 more
Floyd K. Haskell D 457,545 · Gordon Allott R 447,957 · Sedundino Salazar L 13,228 · Henry J. Olshaw I 7,363
Peter H. Dominick R 459,952 · Stephen L. McNichols D 325,584
Peter H. Dominick R 328,655 · John A. Carroll D 279,586 · Charlotte Benson S 3,546 · Henry J. Olshaw I 1,217 · +1 more
John A. Carroll D 319,872 · Daniel I. J. Thornton R 317,102
Gordon Allott R 248,502 · John A. Carroll D 235,686
Eugene D. Millikin R 239,724 · John A. Carroll D 210,442
Edward C. Johnson D 340,719 · William F. Nicholson R 165,069 · Joe Gurule P 2,981 · Carle Whithead S 1,352
Eugene D. Millikin R 191,517 · James A. Marsh D 143,817
Edward C. Johnson D 174,612 · Ralph L. Carr R 170,970 · Carle Whitehead S 1,387 · James Allander C 627
Alva B. Adams D 262,806 · Archibald A. Lee R 181,297 · Carle Whitehead S 3,604 · James Allander I 3,522
Edward C. Johnson D 299,376 · Raymond L. Sauter R 166,308 · Carle Whitehead S 4,438 · George W. Carleton N 1,705
Edward P. Costigan D 180,028 · George H. Shaw R 137,487 · Morton Alexander S 1,745 · H. H. Marra F 1,367 · +3 more
Charles W. Waterman R 149,585 · William E. Sweet D 138,113 · Morton Alexander F 5,829 · Frank H. Rice S 2,218 · +2 more
Lawrence C. Phipps R 159,698 · Alva B. Adams D 139,660 · Morton Alexander F 16,039 · Elwood Hillis S 1,575 · +1 more
Samuel D. Nicholson R 156,577 · Tully Scott D 112,890 · G. F. Stevens F 9,041 · Charles S. Thomas N 8,665
Charles S. Thomas D 102,037 · Hubert Work R 98,728 · Benjamin Griffith P 27,072 · J. C. Griffiths S 13,943 · +1 more