The St. Louis Cardinals 1984 season was the team's 103rd season in St. Louis, Missouri and the 93rd season in the National League. The Cardinals went 84-78 during the season and finished 3rd in the National League East, 12½ games behind their arch-rivals, the Chicago Cubs. It was also the final season of the Columbia blue road uniforms for the Cardinals.
The team wore the same uniforms for the following season.