The 1980 Montana Senate election took place on November 4, 1980, with the primary election held on June 3, 1980. Montana voters elected 25 of the 50 members of the Montana Senate. The election coincided with United States national elections and Montana state elections, including U.S. President, U.S. House, Montana Governor, and Montana House.
Following the previous election in 1978, Republicans held a 26-to-24 seat majority over Democrats. Additionally, after being re-elected in 1978 as a Democrat, Senator John E. Manley of district 14 switched political party affiliation in 1979 to Republican, increasing the GOP's majority to 27 seats.
Republicans increased their majority in the legislature to 29 seats, while Democrats held 21âÂÂgiving Republicans a net gain of two seats. The newly elected members served in the 47th Montana State Legislature, during which Republican Jean A. Turnage was elected President of the Montana Senate.
Italics denote an open seat held by the incumbent party; bold text denotes a gain for a party. Only districts that held elections are listed below.