The school began in 1890, first in two houses in Valetta Street, Malvern, then in an old house in Pine Grove, and, from 1900, in a two storey house in Wattletree Road.
In 1906, Korowa registered as School No 5.
The school relocated to nearby Glen Iris in 1914 within the grace and grandeur of 'Ranfurlie'. This imposing residence originally called 'Everton' was owned by Mr George Kerferd (Premier of Victoria 1874-75) and subsequently the Hon William Knox, MHR who named the home ‘Ranfurlie’, which is now the name of the Crescent in which the school is located.
The School was officially named Corowa in 1899, but later changed to Korowa to avoid confusion with the township of Corowa in 1900.
From 1910 to 1918, it was a Presbyterian school for girls, but in 1919 was incorporated by the Diocesan authorities as a Church of England Grammar School. In 1982, when the Diocese of Melbourne adopted the title Anglican instead of Church of England, the school became Korowa Anglican Girls' School.
In 1989, Korowa became a Corporation limited by guarantee, whose nominated Council members are approved by the Archbishop-in-Council.