StMarys1976

• Kevin Barry (briefly) – Irish republican (executed in 1920)
• Paul Dean – Former Irish and Lions rugby player
• Vincent Dowling – Irish American Director
• Frs. Tom and Earnest Farrell – Founders of the Catholic Boy Scouts of Ireland in 1927
• Larry Gogan – broadcaster
• Denis Hickie – Former Leinster, Irish and Lions rugby player
• Shane Jennings – Former Leinster and Irish rugby player
• Nicholas Kearns – Judge of the Irish Supreme Court
• Kieran Lewis – FormerMunster player
• Darragh MacAnthony – Chairman of Peterborough United FC
• Ronan McCormack – Former Leinster and UCD Rugby Player
• Jack McGrath – Leinster and Irish rugby player
• Rodney O'Donnell – Former Leinster, Irish and Lions rugby player
• Tom O'Higgins – former Chief Justice of Irish Supreme Court
• David O'Sullivan, Director General for EU Trade
• John Mark Redmond – cardiothoracic surgeon and businessperson
• Eoin Ryan – former MEP for Dublin
• Jonathan Sexton – Leinster, Irish and Lions rugby player [1]
• Tony Ward – Former Irish and Lions rugby player and League of Ireland footballer,
• Stephen Grissing - Former Leinster Rugby Player. Chief baller Davy [2]

Notable staff

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