|Reference style||The Most Reverend|
|Spoken style||Your Grace or Archbishop|
After his education at the Propaganda College in Rome, he was the Parish Priest of Kilcock and Vicar General of Kildare and Leighlin. He was appointed the Titular Bishop of Oropus and Coadjutor of Kildare and Leighlin on 20 June 1781. The following year, he was appointed the Coadjutor and Administrator of the Metropolitan see of Armagh on 26 February 1782. On the death of Archbishop Anthony Blake of Armagh on 11 November 1787, O'Reilly automatically succeeded as archbishop and primate.
- Brady, W. Maziere (1876). The Episcopal Succession in England, Scotland and Ireland, A.D. 1400 to 1875. Volume 1. Rome: Tipografia Della Pace.
- Fryde, E. B.; Greenway, D. E.; Porter, S. et al., eds. (1986). Handbook of British Chronology (3rd, reprinted 2003 ed.). Cambridge: Cambridge University Press. ISBN 0-521-56350-X.
|Catholic Church titles|
|Archbishop of Armagh
and Primate of All Ireland