The 2020 Montana gubernatorial election was held on November 3, 2020, to elect the next governor of Montana, concurrently with the U.S. presidential election, as well as elections to the U.S. Senate and the House of Representatives and various state and local elections. It resulted in voters selecting Greg Gianforte over Mike Cooney. Incumbent Democratic governor Steve Bullock was term-limited and could not seek a third consecutive term in office, and he ran unsuccessfully for Montana's Class II Senate seat.
Bullock's lieutenant governor, Mike Cooney, was the Democratic nominee, while the Republican nominee was Montana's at-large congressman Greg Gianforte, who won the election, making him the first Republican governor of Montana since Judy Martz left office in 2005. This was the only gubernatorial seat to change partisan control in the 2020 elections. This election marked the first time since the 1920s that Republicans controlled all state constitutional offices and a majority of the Legislature.
Democratic primary
Candidates
Nominee
Mike Cooney, Lieutenant Governor of Montana and former Secretary of State of Montana and candidate in 2000
Running mate: Casey Schreiner, Minority Leader of the Montana House of Representatives
Eliminated in primary
Whitney Williams, businesswoman and daughter of former U.S. Representative Pat Williams
Running mate: Buzz Mattelin, farmer and president of the National Barley Growers Association
Withdrawn
Reilly Neill, former state representative
Casey Schreiner, Minority Leader of the Montana House of Representatives (running for Lieutenant Governor)
Declined
Ryan Busse, businessman
Wilmot Collins, Mayor of Helena and former 2020 candidate for the U.S. Senate
John Heenan, attorney and candidate for Montana's at-large congressional district in 2018
Michael Punke, writer and former U.S. Ambassador to the World Trade Organization
Brian Schweitzer, former Governor of Montana (endorsed Williams)
Kathleen Williams, former state representative and nominee for Montana's at-large congressional district in 2018 (running for the U.S. House)
Endorsements
Polling
Polls with a sample size of <100 have their sample size entries marked in red to indicate a lack of reliability.
Results
Republican primary
Candidates
Nominee
Greg Gianforte, incumbent U.S. Representative for Montana's at-large congressional district and nominee for Governor of Montana in 2016
Running mate: Kristen Juras, businesswoman and attorney
Eliminated in primary
Tim Fox, Attorney General of Montana
Running mate: Jon Knokey, former state representative
Albert Olszewski, state senator and candidate for U.S. Senate in 2018
Running mate: Kenneth Bogner, state senator
Withdrawn
Gary Perry, former state senator
Corey Stapleton, Secretary of State of Montana, candidate for Governor of Montana in 2012 and candidate for the U.S. House in 2014 (running for the U.S. House)
Pete Ziehli
Declined
Matt Rosendale, Montana State Auditor and nominee for the U.S. Senate in 2018 (running for the U.S. House)
Ryan Zinke, former United States Secretary of Interior and former U.S. Representative for Montana's at-large congressional district
Endorsements
Polling
Polls with a sample size of <100 have their sample size entries marked in red to indicate a lack of reliability.
Results
Other candidates
Libertarian Party
Nominee
Lyman Bishop, founder and CEO of Hoplite Armor
Running mate: John Nesper
Withdrawn
Ron Vandevender, nominee for lieutenant governor in 2016 and nominee for governor in 2012
Green Party
Disqualified
Robert Barb
Running mate: Joshua Thomas
Results
General election
Debate
Predictions
Endorsements
Polling
Results
Results by county
Counties that flipped from Democratic to Republican