In the mid 1970’s a seven acre site on Idrone Avenue was purchased by the priests of Ballroan Parish at a cost of £36,000 for a school in the Knocklyon area. The Carmelite Order took on the task of running the new parish. There were long delays in getting formal approval for the government grant but approval was finally received in April 1975. Mr. John CArroll was architect for the project. The 16 classroom school was completed in July 1976. The school took in it’s first pupils in September 1976 and was officially opened on 31st March, 1977, by the then Taoiseach, Mr. Liam Cosgrave T.D. who resides on Scholarstown Road. Archbishop Dermot Ryan blessed the new building.

The first roll had 47 pupils and by the official opening day this had risen to 54. The population increase in Knocklyon was of such a nature that a second school was required. In 1982 a second building was built. The original school became the Junior School and the new building housed the Senior School.