The 1971 Pittsburgh Pirates season was the 90th season for the Pittsburgh Pirates franchise; their 85th in the National League. It involved the Pirates finishing first in the National League East with a record of 97 wins and 65 losses. They defeated the San Francisco Giants three games to one in the NLCS and beat the Baltimore Orioles four games to three in the World Series. The Pirates were managed by Danny Murtaugh, and played their first full season at Three Rivers Stadium, which had opened in July the year before.

The Pittsburgh Pirates are an American professional baseball team based in Pittsburgh. The Pirates compete in Major League Baseball (MLB) as a member club of the National League (NL) Central Division. Founded as part of the American Association in 1881 under the name Pittsburgh Alleghenys, the club joined the National League in 1887 and was a member of the National League East from 1969 through 1993. The Pirates have won five World Series championships, nine National League pennants, nine National League East division titles and made three appearances in the Wild Card Game.