1981 Major League Baseball postseason

The 1981 Major League Baseball postseason was the playoff tournament of Major League Baseball for the 1981 season. The season had a players' strike, which lasted from June 12 to July 31, and split the season into two halves. Teams that won their division in each half of the season advanced to the playoffs. Teams faced each other in a League Division Series for the first time, a round of the postseason that did not return until 1995, where it became a permanent addition. The winners of the LDS moved on to the League Championship Series to determine the pennant winners that face each other in the World Series. This was the only postseason where MLB used a divisional-based playoff structure instead of a conference-based one.

In the American League, the New York Yankees and Kansas City Royals both made their fifth appearances in the past six years, the Oakland Athletics returned to the postseason for the first time since 1975, and the Milwaukee Brewers made their first postseason appearance in franchise history, and was only the first of two postseason appearances that the Brewers made during their time in the American League. This was the Yankees’ last postseason appearance until 1995.

In the National League, the Houston Astros made their second straight appearance, the Philadelphia Phillies returned for the fifth time in the past six years, the Los Angeles Dodgers made their fourth appearance in the past six years, and the Montreal Expos made their first postseason appearance in franchise history, and their only appearance during their time in Montreal, as the team did not return to the postseason again until 2012 after they moved to Washington, D.C. to become the Washington Nationals.

The postseason began on October 6, 1981, and ended on October 28, 1981, with the Dodgers defeating the Yankees in six games in the 1981 World Series. It was the fifth title for the Dodgers overall and their first since 1965.