Holy Cross Parish dates from 1879; until then Dundrum was in Booterstown Parish. In 1813 a chapel was built on the site of the present church, behind a row of cottages which after Catholic Emancipation, in 1829, were removed and the chapel enlarged. This was financed by annual charity sermons which were also used to fund schools in a house on Ballinteer Road, where the railed ‘garden’ behind Campbells is now. The Boys School began in 1826 and the Girls School in 1828. A Fr. Powell became the first resident Curate in Dundrum in 1833.
The chapel was ready for dedication in 1837 and on 14th September, the feast of the Holy Cross, Archbishop Murray came to Dundrum to perform the ceremony. A second Curate was appointed in 1850 after the opening of the Asylum, where he was chaplain. The population of south County Dublin grew substantially in the ensuing years, especially in Dundrum after the opening of the railway in 1854. In the 1870s it was decided to demolish the chapel and build a new church. This and the parochial house were designed by George Ashlin and built by Messrs Meade & Son. Behind the church a new schoolhouse, designed by John Robinson, was built by William Richardson of Dundrum.
Following the dedication of the church by Archbishop McCabe on 6th July 1879, it was decided to divide Booterstown Parish, with west of Stillorgan Road becoming Dundrum Parish. Fr. Joseph Hickey had been appointed a Curate in Dundrum in 1865 and on 2nd November he was installed as the first Parish Priest. When he died in 1889, a memorial pulpit was erected which was removed along with the altar rails in the 1960s, after Vatican II.
With the large increase in the local population after WWII the church needed enlargement and this was completed in 1954. The new School on Upper Kilmacud Road had been opened in 1945.
In 1943, Kilmacud and Mount Merrion were separated from Holy Cross and in 1953, when the new church in Bird Avenue was built, Mulvey Park was transferred to it.
In 1974, St Johns Parish, Ballinteer was created leaving Holy Cross Parish as it is today.