1931 Major League Baseball season

1931 MLB season
LeagueAmerican League (AL)
National League (NL)
SportBaseball
DurationRegular season:
  • April 14 – September 27, 1931
World Series:
  • October 1 – October 10, 1931
Number of games154
Number of teams16 (8 per league)
Regular season
Season MVPAL: Lefty Grove (PHA)
NL: Frankie Frisch (SLC)
AL championsPhiladelphia Athletics
  AL runners-upNew York Yankees
NL championsSt. Louis Cardinals
  NL runners-upNew York Giants
World Series
ChampionsSt. Louis Cardinals
  Runners-upPhiladelphia Athletics
MLB seasons
Locations of teams for the 1923–1931 American League seasons
American League

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.