The 1931 major league baseball season began on April 14, 1931. The regular season ended on September 27, with the St. Louis Cardinals and Philadelphia Athletics as the regular season champions of the National League and American League, respectively. The postseason began with Game 1 of the 28th World Series on October 1 and ended with Game 7 on October 10. In a rematch of the prior year's postseason, the Cardinals defeated the Athletics, four games to three. This was the first season that the Baseball Writers' Association of America (BBWAA) selected a Most Valuable Player in each league.

Schedule

The 1931 schedule consisted of 154 games for all teams in the American League and National League, each of which had eight teams. Each team was scheduled to play 22 games against the other seven teams of their respective league. This continued the format put in place since the season (except for ) and would be used until in the American League and in the National League. Opening Day, April 14, featured all sixteen teams, the first time since the season. The final day of the regular season was on September 27, which also saw all sixteen teams play on the final day continuing the trend which began the previous season. This was the first time that both Opening Day and the final day of the season saw all sixteen teams play. The World Series took place between October 1 and October 10.

Rule changes

The 1931 season saw the following rule changes:

Teams

Standings

American League

National League

Postseason

Bracket

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Managerial changes

Off-season

League leaders

American League

1 American League Triple Crown pitching winner

National League

Awards and honors

Home field attendance

Events