Bosmansdam High School was founded in 1971 in Bothasig, a suburb in the Milnerton area in Cape Town, South Africa. Only standard 6 and 7 (currently Grade 8 and 9 ) students were enrolled in 1971, which meant that the Class of 1974 was the first class to graduate from Standard 10.

The school used to serve a huge area from Edgemead to Melkbosstrand until local schools were built in these areas too. At present, the student body mostly comes from Bothasig, Burgundy Estate, Richwood and Summer Greens. The first headmaster was Mr S.S. Blondie Loubser, who was succeeded by Mr Norman Kitley. Mr Kitley was a much-loved educator and continued teaching Mathematics at Bosmansdam High School long after his retirement. He was succeeded by Mr Greg Fillmore (acting headmaster), Mr Jan Nelson, Mr Marius Marx (acting headmaster) and Mr Danie Human, the present headmaster.

The school song was composed by the well-known Dirkie de Villiers and the school badge designed by Cor Pama, probably the best-known heraldist of his era. The school motto, Unitate Fortior (In unity is strength), is now more important and relevant than ever before.

Bosmansdam High School became renowned for producing top athletes who became medal-winners at the annual SA Junior Athletic Championships. Most of them were long jump or triple jump athletes like Vincent McBride, Mark Conradie, Warren Cowley.