Murrough O'Brien, 1st Marquess of Thomond, known from 1777 to 1800 as the 5th Earl of Inchiquin, was an Irish peer, soldier, politician, and Chief of Clan O'Brien.
- Occupation
- politician
- Position held
- Member of Parliament in the Parliament of Ireland, Member of the Privy Council of Ireland, member of the House of Lords, member of the 16th Parliament of Great Britain
- Born
- 1726
- Died
- February 10, 1808