Roman Catholicism is the second largest Christian denomination in the UK (after the Church of England). Something like 7% of the population of England and Wales

Roman Catholicism is the second largest Christian denomination in the UK (after the Church of England). Something like 7% of the population of England and Wales, 16% of the population of Scotland, and 40% of the population of Northern Ireland are Catholic. Catholicism is the dominant religion in many parts of Northern Ireland, and even in some parts of western Scotland.