List of Roman Catholic dioceses in Ireland
This is a comprehensive list of Roman Catholic dioceses in the island of Ireland. Roman Catholicism in Ireland is organised as a single Episcopal Conference encompassing both the Republic of Ireland and Northern Ireland, having been unaffected by the partition of Ireland in 1920–22. There are in total 26 dioceses in Ireland, each led by a diocesan bishop.
Structural changes over the years
The diocesan system of Christian church government in Ireland was set up by the Synod of Rathbreasail in 1111 and modified by the Synod of Kells in 1152, replacing the earlier Celtic Christian monastic model. The island of Ireland is divided into four ecclesiastical provinces each headed by a metropolitan archbishop. The provinces were almost co-extensive with their contemporary civil counterparts. After the Reformation in Ireland, both the Protestant Church of Ireland and the Roman Catholic Church saw themselves as successors to the pre-Reformation church. Most bishops were non-resident during the enforcement of the Penal Laws, but the dioceses continued to exist. Whereas English Catholic dioceses were forbidden by law from having the same name as a diocese of the established Church of England, no such prohibition was made for Irish dioceses.
The Roman Catholic dioceses remained close to the original, with a few notable differences. Firstly, several dioceses with small populations were merged, and now have more than one name to represent their merger. Secondly, the Diocese of Galway was created in 1831 following the abolition of the Wardenship of Galway.
Dr. James Butler 2nd, the Archbishop of Cashel and Emly (1774–91), on being appointed by Rome moved his residence and cathedra from Cashel, favouring Thurles instead, where his successors continue to reign today. Similarly, in the Diocese of Elphin, the Cathedral, which was originally established in the County Roscommon town of Elphin, is now in Sligo.
Another change is that the ancient see of Kilfenora has been administered by the Bishop of Galway in the province of Tuam since the late 19th Century. The correct title of the Bishop is now the Bishop of Galway and Kilmacduagh and Apostolic Administrator of Kilfenora. More recently, the Diocese of Ross merged with the Diocese of Cork to form the Diocese of Cork and Ross in the 1950s.
Unlike most of Europe, the boundaries of the Roman Catholic dioceses in Ireland do not conform with the political border between the Republic of Ireland and Northern Ireland. One archdiocese, and three dioceses straddle the border. Two are wholly in Northern Ireland.
- Archdiocese of Armagh (includes parts of counties Armagh, Londonderry and Tyrone)
- Diocese of Clogher (includes parts of counties Fermanagh and Tyrone)
- Diocese of Derry (includes parts of counties Londonderry, Antrim and Tyrone)
- Diocese of Kilmore (includes parts of County Fermanagh).
- Diocese of Down and Connor (in Northern Ireland).
- Diocese of Dromore (in Northern Ireland).
List of dioceses
Ecclesiastical province of Armagh
Approximating the province of Ulster.
- Archdiocese of Armagh
Ecclesiastical province of Cashel
Approximating the province of Munster.
- Archdiocese of Cashel and Emly
Ecclesiastical province of Dublin
Approximating the province of Leinster.
Ecclesiastical province of Tuam
Approximating the province of Connacht.
- Archdiocese of Tuam
As the diocese of Kilfenora is in the Ecclesiastical province of Cashel, the Bishop Galway and Kilmacduagh is it's Apostolic Administrator rather than bishop.
- Irish Catholic Bishops' Conference
- List of Church of Ireland dioceses for the Anglican church
- List of Roman Catholic dioceses (alphabetical) (including archdioceses)
- List of Roman Catholic dioceses (structured view) (including archdioceses)
- List of Roman Catholic archdioceses (by country and continent)
- Apostolic Nuncio to Ireland
- Category:Roman Catholic cathedrals in Ireland
- In general
-  Irish Bishops Conference - Map of the dioceses of Ireland.
- Catholic-Hierarchy entry.