Kilkenny, and then proceeded to St Patrick's College Maynooth where he was ordained on 24 June 1907 to serve as a priest in the Diocese of Ossory.

In the following August he went to the Diocese of Shrewsbury and worked in the parish of St Alban’s Wallasey, Cheshire.

It was announced on 18 May 1923 that Collier was to be made coadjutor Bishop of Ossory and he received episcopal ordination several months later on 5 August 1928 in St Mary's Cathedral, Kilkenny.

Dr Collier was remembered in one tribute to him as being "responsible for many works which remained in a lasting testimony to his zeal and energy.

A wing in the Ossory diocesan seminary, St. Kieran's College was named after Dr Collier; it opened in 1956.