Baron Inchiquin is one of the older titles in the Peerage of Ireland. It was one of two titles created on 1 July 1543 for Murrough O'Brien, Prince of Thomond, who claimed descent from Brian Boru, a High King of Ireland. The grant of the English titles was conditional upon the abandonment of any Irish titles, the adoption of English customs and laws, pledging of allegiance to the Crown, apostasy from the Catholic Church, and conversion to the Church of Ireland. Murrough was made both Earl of Thomond in the Peerage of Ireland, with remainder to his nephew Donough O'Brien and Baron Inchiquin, with remainder to his male heirs. Following the death of his cousin, Conor Myles John O' Brien in June 2023, Conor John Anthony O' Brien is currently the 19th Baron Inchiquin

The Peerage of Ireland consists of those titles of nobility created by the English monarchs in their capacity as Lord or King of Ireland, or later by monarchs of the United Kingdom of Great Britain and Ireland. It is one of the five divisions of Peerages in the United Kingdom. The creation of such titles came to an end in the 19th century. The ranks of the Irish peerage are duke, marquess, earl, viscount and baron. As of 2016, there were 135 titles in the Peerage of Ireland extant: two dukedoms, ten marquessates, 43 earldoms, 28 viscountcies, and 52 baronies. However, these titles have no official recognition in the Republic of Ireland, with Article 40.2 of the Constitution of Ireland forbidding the state conferring titles of nobility and stating that an Irish citizen may not accept titles of nobility or honour except with the prior approval of the Irish government.