Catholic Church in Ireland
In the 2016 Irish census 78.3% of the population identified as Catholic in Ireland; numbering approximately 3.7 million people. Unlike Catholics in the United States, Ireland has seen a significant decline from the 84.2% who identified as Catholic in the 2011 census.
Protestantism in the United Kingdom
Northern Ireland is now one of the most diverse regions in the UK. Catholicism is still the largest single church in Northern Ireland, but Presbyterians total one-fifth of the population. The Church of Ireland accounts for about one-sixth of the population.