The title Earl of Clare has been created twice in the Peerage of Ireland. Both creations became extinct.
First Creation (1661)
The first creation of the Earldom of Clare was for Charles O'Brien, 7th Baron Ibrackan, on 21 October 1661. The O'Brien family was a prominent Gaelic noble dynasty in Ireland, descended from Brian Boru, High King of Ireland. The Barony of Ibrackan (also spelt Ibrickan) had been created for Murrough O'Brien in 1543, along with the Earldom of Thomond. The first Earl of Clare was a Catholic and a supporter of James II, and his line became closely associated with the Jacobite cause.
Holders of the first creation:
- Charles O'Brien, 1st Earl of Clare (c. 1620–1670)
- Daniel O'Brien, 2nd Earl of Clare (d. 1690), son of the 1st Earl. He served in the Irish Brigade in France.
- Daniel O'Brien, 3rd Earl of Clare (1682–1691), son of the 2nd Earl. He died young and without issue, at which point the title became extinct.
Subsequent members of this family, notably Charles O'Brien, Lord Clare (1673–1706), and Charles O'Brien, 5th Viscount Clare (1693–1761), continued to use the title in France, where they were prominent Jacobite military commanders, even though the earldom was considered extinct in British law.
Second Creation (1789)
The second creation of the Earldom of Clare was for John FitzGibbon, on 10 June 1789. FitzGibbon was a prominent lawyer and politician who served as Attorney General for Ireland and then as Lord Chancellor of Ireland. He was a staunch opponent of Catholic Emancipation and a key figure in the passage of the Acts of Union 1800, which abolished the Irish Parliament. He had previously been created Baron FitzGibbon in 1789 and Viscount FitzGibbon in 1793. The peerage title referred to County Clare, though FitzGibbon's primary landholdings were elsewhere.
Holders of the second creation:
- John FitzGibbon, 1st Earl of Clare (1748–1802)
- John FitzGibbon, 2nd Earl of Clare (1792–1851), son of the 1st Earl. He was a close friend of Lord Byron during their time at Harrow School and Cambridge University. He served as Governor of Bombay.
- Richard Hobart FitzGibbon, 3rd Earl of Clare (1793–1864), brother of the 2nd Earl. He died unmarried and without legitimate issue, at which point the title became extinct.