Missouri's Class 1 United States Senate seat was also up for election on November 6, 2018.

[4][5] Prior to this, Galloway had been appointed to the post by former Governor Jay Nixon in 2015, following the death of Tom Schweich.

[6] Following the Republican victories in the elections on November 8, 2016, for Governor of Missouri, U.S. Senate, Lieutenant Governor, Missouri State Treasurer, Attorney General, and Secretary of State, Galloway and U.S.

Senator Claire McCaskill became the only two remaining Democratic statewide officeholders in Missouri.

Her victory also marks the only Democratic win in a statewide election in the state since 2012.