In the American imagination, to be Irish is to be Catholic. The data, however, is clear: most Irish-Americans are not Catholic, and Irish-Americans make up a minority of Catholics in America. Nearly half of Irish-Americans are Protestant; a third are Catholic. The proportions are more equal (roughly 40 percent each) between those that were raised Catholic or Protestant.
Many Irish-Americans, particularly in the South, are evangelicals. In fact, Michael P. Carroll, a dean at Wilfrid Laurier University in Canada, reports that Irish-Americans make up a larger share of evangelicals in the South (20 percent) than their share of Catholicism elsewhere (16 percent). That’s right—a Southern Baptist is more likely to be Irish than is a Catholic.