The 1991 Pittsburgh Pirates season was the 110th in franchise history; the 105th in the National League. This was their 22nd season at Three Rivers Stadium. For the second consecutive season, the Pirates won the National League East title with a record of 98–64. The Pirates finished the season with the best record in Major League Baseball. They were defeated four games to three by the Atlanta Braves in the NLCS. During the season, John Smiley won 20 games – the last to do so for the Pirates in the 20th century.

Offseason

Regular season

Season standings

Game log

Record vs. opponents

Detailed records

Roster

Opening Day lineup

Awards and honors

1991 Major League Baseball All-Star Game

Player stats

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

National League Championship Series

October 9: Three Rivers Stadium in Pittsburgh, Pennsylvania October 10: Three Rivers Stadium in Pittsburgh, Pennsylvania October 12: Atlanta–Fulton County Stadium in Atlanta October 13: Atlanta–Fulton County Stadium in Atlanta October 14: Atlanta–Fulton County Stadium in Atlanta October 16: Three Rivers Stadium in Pittsburgh, Pennsylvania October 17: Three Rivers Stadium in Pittsburgh, Pennsylvania

Transactions

Farm system