The 1891 Pittsburgh Pirates season was the 10th season of the Pittsburgh Pirates franchise and the 1st season under the "Pirates" name; their 5th place in the National League. The Pirates finished eighth and last in the National League with a record of 55–80.
Regular season
Season standings
Record vs. opponents
Opening Day lineup
Roster
Player stats
Batting
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
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