Montana held its general election on November 3, 2020, deciding 125 legislative seats and 9 statewide offices led by the governorship. No chamber changed party control.
All 10 legislative seats that changed hands went from Democrats to Republicans, all but one of them in the House; Democrats did not win a single Republican-held seat. In Cascade County, around Great Falls, every House seat went Republican. Every incumbent who lost was a Democrat:
Beyond the flips, 2 legislative races finished inside two points, both Democratic Senate holds. Sen. Edith McClafferty (D) kept SD 38 by fewer than 60 votes, and challenger Jim Buterbaugh (R) decided against a recount. Rep. Mark Sweeney (D) moved up to SD 39, beating Suzzann Nordwick (R) by fewer than 150 votes. Another 37 legislative races had only one candidate on the ballot.
Voters approved all 5 statewide measures. I-190 legalized and taxed recreational marijuana, and its companion CI-118 let the state set the legal age at 21; both had to pass for legalization to take effect. LR-130, which bars local governments from regulating firearms, including concealed carry, passed by a comparatively narrow margin for a Republican landslide year. It voided a Missoula ban on guns at polling places and in city parks. C-46 and C-47 updated the constitution's signature-distribution rules for ballot measures to match a 2005 court decision.
Legislature
House (100 seats): 42 D, 58 R before the election, 33 D, 67 R after; control stayed with Republicans.
Senate (50 seats): 20 D, 30 R before the election, 19 D, 31 R after; control stayed with Republicans.