The 1888 Cincinnati Red Stockings season was a season in American baseball. The team finished in fourth place in the American Association with a record of 80–54, 11.5 games behind the St. Louis Browns.

The 1888 St. Louis Browns season was the team's seventh season in St. Louis, Missouri, and its seventh season in the American Association. The Browns went 92–43 during the season and finished first in the American Association, claiming their fourth pennant in a row. In the 1888 World Series, the Browns faced the National League champion New York Giants, losing the series 6 games to 4.