The Florida Marlins' 2004 season was the 12th season for the Major League Baseball (MLB) franchise in the National League. It would begin with the team attempting to improve on their season from 2003, where they were the defending World Series champion, having won the World Series in six games against the New York Yankees. Their manager was Jack McKeon. They played most of their home games at Pro Player Stadium. They played two against the Montreal Expos at Chicago's U.S. Cellular Field due to Hurricane Ivan. The team started off 8–1, but then collapsed and finished with a record of 83–79, third in the National League East, and missed the playoffs.

Offseason

Regular season

Season standings

National League East

Record vs. opponents

Opening Day starters

Transactions

Roster

Player stats

Batting

Starters by position

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

Other batters

''Note: G = Games played; AB = At bats; R = Runs; H = Hits; HR = Home runs; RBI = Runs batted in; Avg. = Batting average; 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; W = Wins; L = Losses; SV = Saves; ERA = Earned run average; SO = Strikeouts

Farm system