The 2018 Idaho Senate election was held on November 6, 2018, to determine which party would control the Idaho Senate for the following two years in the 65th Idaho Legislature. All 35 seats in the Idaho Senate were up for election and the primary was held on May 15, 2018. Prior to the election, 29 seats were held by Republicans and 6 seats were held by Democrats. The general election saw Democrats flip a single seat, thereby meaning that Republicans retained their majority in the State Senate.
Predictions SourceRankingAs of Governing | October 8, 2018
Retirements Republicans District 1: Shawn Keough retired. District 3: Bob Nonini retired. District 14: Marv Hagedorn retired. District 35: Jeff Siddoway retired.
Incumbents defeated In primary Republicans District 33: Tony Potts lost renomination to Dave Lent.
In general Republicans District 5: Dan Foreman lost re-election to David Nelson.
Closest races Seats where the margin of victory was under 10%:
Results District 1
District 2
District 3
District 4
District 5
District 6
District 7
District 8
District 9
District 10
District 11
District 12
District 13
District 14
District 15
District 16
District 17
District 18
District 19
District 20
District 21
District 22
District 23
District 24
District 25
District 26
District 27
District 28
District 29
District 30
District 31
District 32
District 33
District 34
District 35
References