The Junior Cup Rugby teams of 1989, 2003, and 2006 reached the final of the Leinster Schools Junior Cup. The Senior Cup Team (SCT) have reached three semi finals and three finals. The SCT of 2019 reached the final of the Senior Cup for the first time in the college's history, losing to Saint Michael's College. The 2023 team won the school's first ever Senior Cup, beating holders Blackrock with a score of 35-31 on 17 March, 2023. They have also won the Senior League (for middle-ranking schools) on several occasions. The school has produced a small number of professional rugby players and seven Irish internationals: Tony Ensor, John Cooney, Barry Bresnihan (who went on to represent the British and Irish Lions), Padraig Kenny, Kevin McLaughlin, Dominic Ryan, and Matt Healy.
