2021 American League Division Series
The 2021 American League Division Series were the two best-of-five-games series in Major League Baseball’s (MLB) 2021 postseason that determined the participating teams of the 2021 American League Championship Series. The three divisional winners, seeded first through third, and a fourth team—determined by the AL Wild Card Game—played in two series. These matchups were:
- (1) Tampa Bay Rays (AL East champions) vs. (4) Boston Red Sox (Wild Card Game winner): Red Sox win series 3–1.
- (2) Houston Astros (AL West champions) vs. (3) Chicago White Sox (AL Central champions): Astros win series 3–1.
The team with the better regular season record (higher seed) of each series hosted Games 1, 2, and (if necessary) 5, while the lower seeded team hosted Game 3 and (if necessary) 4. Following the series, the Red Sox and Astros met in the 2021 American League Championship Series, with the Astros winning the series, 4 games to 2. The Astros would go on to lose the 2021 World Series to the National League champion Atlanta Braves, 4 games to 2.