The Bishop Allen Academy site is situated on acres on a ravine that runs parallel to the Mimico Creek. It was part of the original piece of land surveyed in the township of Etobicoke in 1793 by local developer Frederick Davidson which was set aside for the use of the government mill or the King's Mill located at the first rapids upstream from Lake Ontario and was later used for his 'Brookwood' estate. The house was eventually demolished in 1961 and the Etobicoke Board of Education constructed Kingsmill Secondary School (named after the Old 'King's' Mill) in 1962 designed by the architectural firm of Gordon S. Adamson & Associates on the 721 Royal York Road building just south of Royal York Collegiate Institute (now used today as Etobicoke School of the Arts). The school was opened in October 1963.