The Diocese of Ossory is a Latin Church diocese of the Catholic Church in eastern Ireland. It is one of three suffragan dioceses in the ecclesiastical province of the Metropolitan Archbishop of Dublin. Currently, it is led by Niall Coll who was appointed on 28 October 2022 and will be ordained bishop on 22 January 2023.

The Archdiocese of Dublin is a Latin Church ecclesiastical territory or archdiocese of the Catholic Church located in the eastern part of Ireland. Its archepiscopal see includes the republic's capital city – Dublin. The cathedral church of the archdiocese is St Mary's Pro-Cathedral. Dublin was formally recognised as a metropolitan province in 1152 by the Synod of Kells. Its second archbishop, Lorcán Ua Tuathail, is also its patron saint.