The 1980 Montreal Expos season was the 12th season in franchise history. The Expos were tied with the division rival Philadelphia Phillies in the standings entering the final weekend of the season with a three game series set between the two clubs at Olympic Stadium. On October 4, with the Phillies holding a one-game lead in the standings, and with the score tied at four heading to the tenth, Mike Schmidt hit a blast deep into the seats in left field to give the Phillies a 6–4 lead and ultimate win to clinch the National League East. This was the Expos closest shot at making the postseason in their brief 12 year history.

Offseason

Spring training

In 1980, the Expos held spring training at City Island Ball Park in Daytona Beach, Florida, for the final time. It was their eighth season there. For spring training the following season, they would return to West Palm Beach Municipal Stadium in West Palm Beach, Florida, where they previously had trained from 1969 through 1972.

Regular season

On June 8, during a doubleheader against the St. Louis Cardinals, the Expos played against two different Cardinals managers: Ken Boyer, who was fired between games, and his replacement, Jack Krol.

Season standings

Record vs. opponents

Opening Day starters

Notable transactions

Roster

Player stats

Batting

Starters by position

''Note: Pos = Position; G = Games played; AB = At bats; R = Runs; H = Hits; Avg. = Batting average; HR = Home runs; RBI = Runs batted in; SB = Stolen bases''

Other batters

''Note: G = Games played; AB = At bats; R = Runs; H = Hits; Avg. = Batting average; HR = Home runs; RBI = Runs batted in; SB = Stolen bases''

Pitching

Starting pitchers

Note: G = Games pitched; IP = Innings pitched; W = Wins; L = Losses; ERA = Earned run average; SO = Strikeouts

Other pitchers

Note: G = Games pitched; IP = Innings pitched; W = Wins; L = Losses; ERA = Earned run average; SO = Strikeouts

Relief pitchers

Note: G = Games pitched; IP = Innings pitched; W = Wins; L = Losses; SV = Saves; ERA = Earned run average; SO = Strikeouts

Awards and honors

1980 Major League Baseball All-Star Game

Farm system