St Mary’s College C.S.Sp. is a long-established voluntary Catholic boys’ school located in Rathmines, Dublin. Founded in 1890 by the Congregation of the Holy Spirit, the college serves students from Junior Infants through Sixth Year and maintains an enrolment of roughly 700 pupils. Guided by its Spiritan heritage and its motto Fidelitas in Arduis (“Faithful in difficulty”), the school is known for strong academic foundations, a committed staff, and a distinctive community ethos.
The college originally opened in 1890, closed temporarily in 1916, and reopened in 1926 after serving as a House of Philosophy for the Spiritans. Today, St Mary’s operates with both primary and secondary sections on a shared urban campus. The school is directly connected to a wider network of Spiritan institutions in Ireland, including Blackrock College, St Michael’s College, Rockwell College, and Templeogue College.
Rugby plays a central role in student life. St Mary’s has produced several Leinster, Ireland, and British and Irish Lions players, and its long-standing partnership with St Mary’s College RFC in Templeogue has created one of the country’s most influential school-club pathways. Notable rugby alumni include Rodney O’Donnell, Paul Dean, Denis Hickie, Shane Jennings, Johnny Sexton, and World Rugby Sevens Player of the Year Terry Kennedy.
St Mary’s past pupils have also made their mark in law, politics, and the arts, including Supreme Court Justice Peter Charleton, former Chief Justice Tom O’Higgins, novelist and director Vincent Dowling, and historical figure Kevin Barry. Éamon de Valera briefly taught mathematics at the school in 1915 before entering national politics.
With its Spiritan identity, strong academic tradition, and rich sporting culture, St Mary’s College remains one of Dublin’s most respected Catholic schools.