Sandymount High School was founded in 1947 and was initially controversial because, as a non-denominational school, it wasn't owned by a church but by the Cannon family,^[1] who also provided the two headmasters the school had: father and son Patrick and Conall Cannon. Patrick's wife Eileen Cannon also served as headmistress.^{[citation needed]}

The school's student body included those from a local council estate called Beech Hill, the offspring of parents disenchanted with denominational/same sex schools, students on the Malahide/Howth to Bray rail corridor and foreign nationals who paid tuition fees.^{[citation needed]}

While the school had a gym — basically exercise classes — for Intermediate Certificate students, it had no compulsory sports or sports team for a period.^{[citation needed]} Otherwise rugby union was the main school sport for both Intermediate and Leaving Certificate male students during the early 1960s.^{[citation needed]}

A rival school opened next door several years later: Marian College, run by the Catholic Church. It was originally intended to be co-educational and named Riverside College, but both the name and its co-educational character were changed at the insistence of John Charles McQuaid as he disliked the influence of Sandymount High.^[2]

The school was closed in 1999 and the land sold for development.^[3] The site now contains a gated community called Cannon Place.^{[citation needed]}

Notable former pupils include Fionnula Flanagan,^[4] Charlie Bird,^[5] Eamonn Dunphy,^[6] Dervla Kirwan^{[citation needed]} and Ronnie Delaney.^{[citation needed]}

53°20′01″N 6°13′32″W / 53.3335°N 6.2255°W / 53.3335; -6.2255