St. Mochta's were founded in September 1949 when founder Barth O'Brien put a motion to the AGM of the St. Mochta's Branch of the Catholic Young Men's Society (CYMS) that a football section be formed within the branch.

[1] In its early years, the club played its football at Somerton on the same grounds where Castleknock GAA club now play and briefly in Coolmine Lane, close to Coolmine railway station before permanently establishing themselves at Porterstown.

[3] In July 2019, the club celebrated its 70th anniversary with a glamour friendly tie against English League One side Bristol Rovers.

Hailed as 'the biggest club the .... side have ever played',[4] the match ended in a 7–0 loss for St.

[5] The club were runners up in the 2023–24 Leinster Senior Cup, losing 3–1 to St Patrick's Athletic at Richmond Park on 8 October 2024.