The 1903 Brooklyn Superbas season was a season in Major League Baseball. The Superbas began their slide from contention in the National League by finishing in fifth place.

The 1903 major league baseball season began on April 16, 1903. The regular season ended September 29, with the Pittsburgh Pirates and the Boston Americans as regular season champions of the National League and American League, respectively. The postseason began with Game 1 of the first modern World Series on October 1 and ended with Game 8 on October 13. The Americans defeated the Pirates, five games to three.