1921 Brooklyn Robins season

Staff ace Burleigh Grimes won 22 games, but the 1921 Brooklyn Robins fell into fifth place.

Offseason

 * December 15, 1920: Rube Marquard was traded by the Robins to the Cincinnati Reds for Dutch Ruether.

Notable transactions

 * June 18, 1921: Jeff Pfeffer was traded by the Robins to the St. Louis Cardinals for Ferdie Schupp and Hal Janvrin.
 * August 31, 1921: Eddie Eayrs was purchased by the Robins from the Boston Braves.

Starters by position
''Note: Pos = Position; G = Games played; AB = At bats; H = Hits; Avg. = Batting average; HR = Home runs; RBI = Runs batted in''

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

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