St Mary's College Rugby Football Club is a rugby union club based in South Dublin, Ireland, playing in Division 1B of the All-Ireland League. The club was founded in 1900 by former pupils of St. Mary's College, Dublin and was originally known as Old St Mary's. They club won the Leinster Senior Cup for the first time in 1958. In 2000 they won the AIB League for the first time under the captaincy of Trevor Brennan.