1886 Major League Baseball season

1886 MLB season
LeagueAmerican Association (AA)
National League (NL)
SportBaseball
DurationRegular season:
  • April 17 – October 15, 1886 (AA)
  • April 29 – October 11, 1886 (NL)
World's Championship Series:
  • October 18–23, 1886
Number of games140 (AA)
126 (NL)
Number of teams16 (8 per league)
Pennant winner
AA championsSt. Louis Browns
  AA runners-upPittsburgh Alleghenys
NL championsChicago White Stockings
  NL runners-upDetroit Wolverines
World's Championship Series
ChampionsSt. Louis Browns
  Runners-upChicago White Stockings
Locations of teams for the 1886 American Association season
American Association

The 1886 major league baseball season began on April 17, 1886. The regular season ended on October 15, with the Chicago White Stockings and the St. Louis Browns as regular season champions of the National League and American Association, respectively. The postseason began with Game 1 of the third World's Championship Series on October 18 and ended with Game 6 on October 23, in what was a best-of-seven-playoff. The Browns defeated the White Stockings, four games to two, capturing their first World's Championship Series.

Over the offseason, the National League's Buffalo Bisons transfer into the minor league International League and Providence Grays fold. The two open spots are filled by the newly enfranchised Kansas City Cowboys and Washington Nationals.