The 1983–84 Major Indoor Soccer League season was the sixth in league history and ended with the Baltimore Blast winning their first MISL championship. The Blast would beat the St. Louis Steamers in the championship series, the third time in five seasons the Steamers would lose in the MISL championship round. This would be the first time the MISL finals would be a best-of-seven series, part of the league's expanded playoff format.