List of Catholic dioceses in Great Britain and Ireland may refer to:
List of Catholic dioceses in Great Britain List of Catholic dioceses in Scotland List of Catholic dioceses in England and Wales List of Catholic dioceses in Ireland
The Catholic Church is not organised on a state basis in the United Kingdom. In the island of Great Britain, the Church is organised into two separate hierarchies or episcopal conferences: the Catholic Church in England and Wales, and the Catholic Church in Scotland. In the island of Ireland, while Northern Ireland is a constitutional part of the United Kingdom, no separate episcopal conference exists for Northern Ireland; instead, the Church is part of the hierarchy or episcopal conferences of the Catholic Church in Ireland. There are also a number of Eastern Catholic dioceses in the UK.