It competes in the Isle of Man Football League wearing a yellow and green kit.

[1] In 1983–84, the club was relegated to Division Two, finishing in last place, winning just one league game all season.

[3] In 1995–96 the club was Isle of Man champion for the second time[4] and won the Hospital Cup beating St Georges 1–0 in the final.

[3] In the following season, St Marys finished third in the league,[5] won the Railway Cup with a 2–0 victory over Rushen United and was the losing finalist in the Hospital Cup[3] before winning the title again in 1997–98, winning all 25 games, scoring 93 goals and conceding just 14 times.

[8] In the following season, it was Isle of Man champion for the third time and won the Hospital Cup, beating Rushen United 1–0 in the final.