[4] During his semester breaks it was reported that he pulled beers at the Majellan Club, carted feed and cut cauliflowers in the local market gardens.

[5] Ordained as a priest at St Michael and St John's Cathedral in Bathurst on 2 September 1983, O'Regan served as an assistant parish priest in parishes in Lithgow, Cowra, Orange and in Bathurst.

He returned to Australia, initially to Orange, before being appointed as a parish priest in Wellington.

O'Regan completed his higher studies in France during 2001 and 2002 graduating with a Licentiate in Liturgy and Sacramental Theology;[6] returning to Australia in 2003 as parish priest of Blayney.

[4] In December 2014 it was announced that Pope Francis had appointed O'Regan as the Bishop of Sale, replacing Christopher Prowse, who became the Archbishop of Canberra-Goulburn.