1978 Montana Senate election
The 1978 Montana Senate election took place on November 7, 1978, with the primary election held on June 6, 1978. Montana voters elected 27 of the 50 members of the Montana Senate. The election coincided with United States national elections and Montana state elections, including U.S. Senate, U.S. House, and Montana House.
Following the previous election in 1976, the chamber was tied with both Democrats and Republicans holding 25 seats. Republicans flipped control of the chamber in 1978 by winning 26 seats while Democrats held 24—giving Republicans a net gain of one seat. The newly elected members served in the 46th Montana State Legislature, during which Republican William L. Mathers was elected President of the Montana Senate.
Retiring incumbents
Democrats
- District 6: W. Gordon McOmber
- District 11: Joe R. Roberts
- District 19: John W. “Jack” Devine
- District 43: Robert E. "Bob" Lee
- District 46: Miles Romney
Incumbent defeated in primary election
Democrat
- District 48: Elmer Flynn
Incumbents defeated in general election
Democrats
- District 18: Margaret S. Warden
- District 40: Terry Murphy
Republicans
- District 15: Frank Dunkle
- District 36: L. M. “Larry” Aber
- District 50: William E. "Bill" Murray
Summary of results
Italics denote an open seat held by the incumbent party; bold text denotes a gain for a party.Detailed results by district
District 15
District 34
District 43
- District 43 held a special election to fill the last two years of a vacated term.
District 50
- District 50 held a special election to fill the last two years of a vacated term.