St. Matthias’ Church is located in the parish of Killiney/Ballybrack, in the heart of South County Dublin. The parish motto, “Embracing life in all its fullness”, is taken from John’s Gospel chapter 10 verse 10. This Church of Ireland is in the United Dioceses of Dublin and Glendalough.

Holy Trinity Church, the ‘church on the hill’ as it has often been called, is the parish church of the area in which the school is located.

It was built in 1859- just 3 years after the railway line passing through Killiney was laid. The railway line with its various stations on the route made way for the building of many houses in the area and hence the need for a church. The church was built on part of the grounds of Killiney Castle, then owned by Robert Warren who paid a considerable amount of the cost of the building and whose nephew, Sandham Symes, was the architect of the church.

One of the treasures of the church is a window designed and created by the famous Harry Clarke. The title of the window is ‘Angel of Peace’ or ‘Angel of Hope,’ and people come from all around the world to see it.  For many years the school for this parish was on Killiney Hill Road, at its junction with Strathmore Road. Over 30 years ago, this school was combined with Glenageary School, and the present school was built to accommodate the combined schools.

Worship in the church continues Sunday by Sunday, just as it has done for over 150 years. The Carry Centre across the road from the church is a hub for community and parochial activities throughout the week, and Sunday Club for children is held there on many Sundays of the year.