In 1860, Bishop Harding and the Cathedral Chaplain opened a grammar school within the walled city of Bombay along with a smaller establishment for girls.

[8][9] A Choir School was established in 1875 with the objective of providing choristers for the St. Thomas Cathedral, Mumbai, the first Anglican Church in the city.

The society put up a building on the Esplanade, and named it for John Connon (then Chief Registrar of Bombay).

The IB arm of the school, set up in 2015, planned to move to the Deutsche Bank Building (formerly Tata Palace) by 2018.

[11] However, a later decision by the Dean, Dr. Sonal Parmar converted the building into a section for the 11th and 12th standard of both the IB and ISC curricula.

Miss Whitfield, the Principal of the Girls' School, wanted a badge which was representative of both elements of the Society: Anglican and Scottish.

A badge was designed in which the Bishop's Mitre represented the Anglican side, while the Scottish neighbours were symbolised by the white diagonal cross of St. Andrew.

2011 featured the first international delegates from Rato Bangala School from Nepal and Aitchinson College, Pakistan.