Please be mindful of WP:BLPCAT when adding this category to a biography, namely: "Categories regarding religious beliefs (or lack of such) or sexual orientation should not be used unless the subject has publicly self-identified with the belief (or lack of such) or orientation in question, and the subject's beliefs or sexual orientation are relevant to their public life or notability, according to reliable published sources."

While this category is for Irish Catholics who are not or were not Roman Catholics, note that there is a subcategory, Category:Irish Roman Catholics, for those who are or were notable Roman Catholics.