In 1813, Margaret Godfrey inherited a large tract of land from her husband, Louis Chaboillez. She yielded many plots of land to the City of Montreal including the lot known as Chaboillez Square (which was larger than it is today).
The Square was completely refurbished in 1950 and reopened in 1953. Its size was reduced in the mid-1960s in planning for the coming of the Ville Marie Expressway. The Dow Planetarium (later known as Montreal Planetarium) was constructed in the square in 1966.