The school was founded by the Sisters of Mercy on 1 November 1925. In 1926 the church / school of St Therese was built in Royal St New Lambton some 200 yards from the present church. As was common at the time, it was a dual purpose building being used for mass on Sundays and for classes during the week. In style it was similar to many others of its type being a simple hall capable of being partitioned into separate rooms with a chancel and sacristy, closed off except during mass. A small porch was attached while gable crosses proclaimed this to be a house of god. It served as the parish church from 1954 until 1956, when it was converted to serve, as it still does today, as a hall for the parish and school.