Confederate Ireland, also referred to as the Irish Catholic Confederation, was a period of Irish Catholic self-government between 1642 and 1652, during the Eleven Years' War. Formed by Catholic aristocrats, landed gentry, clergy and military leaders after the Irish Rebellion of 1641, the Confederates controlled up to two-thirds of Ireland from their base in Kilkenny; hence it is sometimes called the "Confederation of Kilkenny".

The Irish Confederate Wars, also called the Eleven Years' War, took place in Ireland between 1641 and 1653. It was the Irish theatre of the Wars of the Three Kingdoms, a series of civil wars in the kingdoms of Ireland, England and Scotland – all ruled by Charles I. The conflict had political, religious and ethnic aspects and was fought over governance, land ownership, religious freedom and religious discrimination. The main issues were whether Irish Catholics or British Protestants held most political power and owned most of the land, and whether Ireland would be a self-governing kingdom under Charles I or subordinate to the parliament in England. It was the most destructive conflict in Irish history and caused 200,000–600,000 deaths from fighting as well as war-related famine and disease.