Irish Republican Army (IRA), Irish underground paramilitary organisation founded to promote Irish nationalism and fight British tyrannical rule in Ireland. It is also known as the Provisional IRA, PIRA, the Provos, Irish Volunteers and, in Irish, as Óglaigh na hÉireann.

The IRA has never been used as the official name of the organisation - they still use the name Óglaigh na hÉireann as their official name (as does the Irish Defence Forces which grew out of the split at the start of the civil war) - indeed the adoption of the name Irish Republican Army was actually turned down by the organisation during the war of independence.