Opened 28 April 1963, Immaculate Heart of Mary replaced the original school on this site, St. Nicholas School, constructed in 1911. Served by the Sisters of Mary Immaculate, its mission was to provide a Ukrainian-Catholic education to children from all parishes.
- Along with a new name of Immaculate Heart of Mary, the new school had the old cornerstone built into its entrance; a cornerstone on the gym for 1962 indicates that it was the first section completed before the old school was demolished
- Initially, 241 students from kindergarten to Grade 12 attended classes but two years later the senior high was eliminated and the school settled into its K-8 program; it now offers junior kindergarten to Grade 8, with a before-and-after daycare program
- The school's design was considered "ultra-modern", fitted with many windows for natural light and constructed with high quality materials such a terrazzo floors and fine wood panelling, even wall-to-wall carpeting, to reduce future maintenance costs
- While there have been alterations to the exterior, the school looks essentially as it did upon opening and changes have been done with care and sensitivity; windows have been replaced in each classroom but they are very close to the original type
- There is a two-storey academic wing running eas-west parallel to the street joined perpendicularly to the gym wing; the end walls and all four walls of the gym wing are faced in limestone; the side walls of the classrooms are mostly glass and candidly reveal the steel frame; the south facing walls project out at the window bays (now behind screens)
- Although somewhat constrained in its site, the school has both a paved and grassed play area adjacent and it purchased a lot behind its lane for more green space and a play structure