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.
County Donegal
Although approximately 85% of its population is Roman Catholic, County Donegal also has a sizeable minority of Ulster Protestants. Many Donegal Protestants trace their ancestors to settlers who arrived during the Plantation of Ulster in the early 17th century. The Church of Ireland is the largest Protestant denomination but is closely rivalled by a large number of Presbyterians. The areas of Donegal with the highest percentage of Protestants are The Laggan area of East Donegal around Raphoe, the Finn Valley and areas around Ramelton, Milford and Dunfanaghy – where their proportion reaches up to 30–45 percent. There is also a large Protestant population between Donegal Town and Ballyshannon in the south of the county. In absolute terms, Letterkenny has the largest number of Protestants (over 1000) and is the most Presbyterian town (among those settlements with more than 3000 people) in the Republic of Ireland.