St Mary's College C.S.Sp. (Congregatio Sancti Spiritus) is a voluntary boys' primary and secondary school run by the Congregation of the Holy Spirit and located in Rathmines, Dublin, Ireland. The school was founded in 1890, closed in 1916, and then reopened in 1926 (from 1917 until 1926 the St. Mary's operated as a House of Philosophy for the Spiritans, before it moved to Blackrock.). The school colours are blue and white.

Notable past pupils

This article's list of alumni may not follow Wikipedia's verifiability policy. Please improve this article by removing names that do not have independent reliable sources showing they merit inclusion in this article AND are alumni, or by incorporating the relevant publications into the body of the article through appropriate citations. (March 2024)

Arts and media

• Vincent Dowling – Irish-American director

Law

• Peter Charleton — Judge of the Supreme Court of Ireland
• Nicholas Kearns – Former President of the High Court of Ireland
• Tom O'Higgins – Former Chief Justice of the Supreme Court

Politics

• Kevin Barry (briefly) – Irish republican (executed in 1920)

Sports

• Rodney O'Donnell – Former Leinster, Irish and Lions rugby player
• Paul Dean – Former Irish and Lions rugby player
• Denis Hickie – Former Leinster, Irish and Lions rugby player
• Shane Jennings – Former Leinster, Leicester tigers, barbarians and Irish rugby player
• Johnny Sexton – Leinster, racing 92, Irish and Lions rugby player
• Gareth Delany — Irish cricketer

Other

• Peter Boylan — Former Master of the National Maternity Hospital

Notable staff

• Éamon de Valera – Taoiseach and former president, taught at St. Mary's for a short time in 1915 as a mathematics professor

Sister schools

The following schools were also founded by the Holy Ghost Fathers in Ireland:

• Blackrock College
• Rockwell College
• St. Michael's College
• Templeogue College

St. Mary's College Rugby Club

Saint Mary's College C.S.Sp. is directly associated with the St. Mary's College Rugby Club located in Templeogue. The club has been home to some of Leinster and Ireland's greatest rugby players.