The 2018 South Dakota Senate election was held on November 6, 2018, to determine which party would control the South Dakota Senate for the following two years in the 94th South Dakota Legislature. All 35 seats in the South Dakota Senate were up for election and the primary was held on June 5, 2018. Prior to the election, 29 seats were held by Republicans and 6 seats were held by Democrats. The general election saw Republicans expanding their majority in the State Senate by a single seat.
Predictions
Retirements
Democrats
- District 1: Jason Frerichs was term-limited.
- District 21: Billie Sutton was term-limited and went on to unsuccessfully run for governor of South Dakota.
- District 27: Kevin Killer retired.
Republicans
- District 5: Neal Tapio retired to unsuccessfully run for South Dakota's at-large congressional district.
- District 7: Larry Tidemann was term-limited.
- District 9: Deb Peters was term-limited.
- District 10: Jenna Netherton resigned on April 10, 2018.
- District 35: Terri Haverly retired.
Closest races
Seats where the margin of victory was under 10%:
- (gain)
Results
References