The Philadelphia Phillies' 2011 season was the 129th season in the history of the franchise. The Phillies won their fifth consecutive National League East championship, and also finished with the best record in baseball for the second straight year. The Phillies, at 3–1 odds, were the heavy-favorite to win the World Series. However, they were eliminated in the NLDS in five games by the eventual World Series champion St. Louis Cardinals. This was the last season that the Phillies made the postseason until 2022, making it the longest active postseason drought in the National League at the time. The 2011 Phillies were the last team until the 2015 Cardinals to finish the season with at least 100 wins.

The 2011 World Series was the championship series of Major League Baseball's (MLB) 2011 season. The 107th edition of the World Series, it was a best-of-seven playoff played between the American League (AL) champion Texas Rangers and the National League (NL) champion St. Louis Cardinals; the Cardinals defeated the Rangers in seven games to win their 11th World Series championship and their second in six seasons.