The origins of the Parish of St John’s Wood / The Gap go back to 1936 when Archbishop Duhig invited the Marist Fathers to take on the growing district of St John’s Wood in Ashgrove Parish. The Marist Fathers were resident in the area at Glenlyon House and had been attracting many parishioners to their Chapel services. Masses continued in the Chapel throughout 1936 until numbers were such that services commenced at the Ambassador’s Hall, St John’s Wood.

On Sunday 18th April 1937, the foundation stone of Mater Dei church was laid. Three months later, on Sunday 18th July 1937, at 7.00 am a sung Mass by the Wilston choir was the first celebration for the official opening of the new Mater Dei Church by Archbishop James Duhig in the afternoon of that day.

School began at Mater Dei on 5th February, 1951, with an attendance of 50-55 students.

Mater Dei church was enlarged twice over the years to cope with the increasing number of parishioners and then 9.12.1962 saw the blessing and opening of the Mater Dei Convent. Several Sisters of Charity lived in community at the new convent for the next twelve years, but eventually withdrew due to a shortage of vocations and returned to live at Mt St Michael’s convent.

On 9th November 1969 a special Mass was celebrated on the new ten acre property in Chaprowe Rd, The Gap. At that time Mater Dei church, which had seating capacity for 320, held four Masses each Sunday. One Mass each Sunday was held in The Gap RSL. St Peter Chanel School opened on 28th August 1972. Mass was celebrated in the school buildings until the first Mass at St Peter Chanel church on 21st December 1980 with the official blessing on the 1st February 1981.

The parish subsequently became known as the Parish of St John’s Wood – The Gap.

The parish was administered by the Marist Fathers until the end of 2008. It is now a diocesan parish.