St. Mary's Episcopal School is a member of the TSSAA, and all sports in the Upper School except Swimming, Dance, and Lacrosse are subject to those rules and regulations.
Members of teams in all sports in the Upper School have participated in a tryout program for that sport. The Athletic Department determines appropriate tryout programs for each sport. Eligibility for team membership is based on skill, academic standing, and good sportsmanship. Sports require a time commitment of a minimum of ten hours each week.