Irish Americans are an ethnic group comprising Americans who have full or partial ancestry from
Ireland, especially those who identify with that ancestry, along with their cultural characteristics. About 33.3 million Americans—10.5% of the total population—reported Irish ancestry in the 2013
American Community Survey conducted by the
U.S. Census Bureau. This compares with a population of 6.4 million on the island of Ireland. Three million people separately identified as
Scotch-Irish, whose ancestors were
Ulster Scots who emigrated from Ireland to the United States.