2020 Oklahoma Senate Election (Alternate Party System)

The 2020 United States Senate election in Oklahoma was held on November 3, 2020, to elect a member of the United States Senate to represent the State of Oklahoma, concurrently with the 2020 U.S. presidential election, as well as other elections to the United States Senate in other states and elections to the United States House of Representatives and various state and local elections. Incumbent Democratic Senator Dan Boren chose not to seek reelection, having served three terms since 2002. Republican represenative for Oklahoma's First District, Kevin Hern, defeated the Democratic nominee Markwayne Mullin, represenative for Oklahoma's Fifth District.

This election was initially expected to be an easy pickup for the Republican party, despite an overwhelmingly Democratic environment nationwide. Although Boren had won his last three elections in landslides, Oklahoma had trended rightwards since the early 2000s, and all polls prior to the election showed a large lead for Hern. Mullin was able to keep the election close, and outperformed the concurrent presidential nominee by ten points.