Anglo-Irish people (Irish: Angla-Éireannach) denotes an ethnic, social and religious grouping consisting mostly of the descendants and successors of the English Protestant Ascendancy in Ireland. Predominantly, the Anglo-Irish belong to the Anglican Church of Ireland, which was the established Church of Ireland until 1871 or, to a lesser extent, to one of the English Dissenting Churches, such as Baptists, Presbyterians, the Methodist Church. However, some were Roman Catholics. They often defined themselves simply as "British", or less frequently as "Anglo-Irish", "Irish" or "English". Many became notable as administrators in the British Empire or as senior army and naval officers. The Kingdom of England and Great Britain were in a real union with the Kingdom of Ireland for over a century, before politically uniting into the United Kingdom of Great Britain and Ireland in 1801.
The term is not usually applied to Presbyterians in the province of Ulster, whose ancestry is mostly Lowland Scottish, rather than English or Irish, and who are sometimes identified as Ulster Scots. The Anglo-Irish hold a wide range of political views, with some being outspoken Irish nationalists, but most overall being Unionists. And while most of the Anglo-Irish originated in the English diaspora in Ireland, others were descended from families of the old Gaelic nobility of Ireland.