The Provisional Irish Republican Army (Irish: Óglaigh na hÉireann) (IRA; also referred to as the PIRA, the Provos, or by some of its supporters as the Army or the 'RA. ) is an Irish Republican, left wing paramilitary organisation that, until the Belfast Agreement, sought to end Northern Ireland's status within the United Kingdom and bring about a United Ireland by force of arms and political persuasion. Since its emergence in 1969, its stated aim has been the overthrow of Northern Ireland and the Republic of Ireland and their replacement by a sovereign socialist all-island Irish state. The organisation is classified as an illegal terrorist group in the United Kingdom blank">Home Office - Proscribed Terror Groups — _Home Office website, retrieved 11 May 2007 and as an illegal organisation in the Republic of Ireland.

The IRA sees itself as a direct continuation of the Irish Republican Army (the army of the Irish Republic — 1919–1921) that fought in the Irish War of Independence. Like all other organisations calling themselves the IRA (see List of IRAs), the Provisionals refer to themselves in public announcements and internal discussions as Óglaigh na hÉireann ("The Irish Volunteers"), which is also the Irish language title of the Irish Defence Forces (the Irish army).

On 28 July 2005, the IRA Army Council announced an end to its armed campaign, stating that it would work to achieve its aims using "purely political and democratic programmes through exclusively peaceful means" and that IRA "Volunteers must not engage in any other activities whatsoever".

An internal British Army document released in 2007 stated an expert opinion that the British Army had failed to defeat the IRA by force of arms but also claims to have 'shown the IRA that it could not achieve its ends through violence'. The military assessment describes the IRA as 'professional, dedicated, highly skilled and resilient'.