It was founded as an elementary school for the small community of Orangeville, to the south of Ottawa. It was known as Hugh Street School, as Kent Street was then named Hugh Street. In 1889 the town was amalgamated with Ottawa, and its one room school house became part of the Ottawa school board, as this part of the city was rapidly growing in 1889, the one-room one-teacher school was overcrowded with a total of 99 students. Thus, in 1897, four new rooms were added, and in 1905 another four. The school was soon renamed Glashan PS, after the Chief Inspector of Ottawa Public Schools from 1876 to 1910, J.C. Glashan. The school was expanded again in 1922 and once more 1931, when it became one amongst a group of Ottawa schools to switch to the pioneering intermediate school format, the school officially became Glashan MS, and has remained a junior high school ever since.