The title of Earl of Clancarty has been created twice in the Peerage of Ireland, first in 1658, that title being attainted in 1690, and then in 1803.

The Earl bears the subsidiary titles of Viscount Dunlo (1801) and Baron Kilconnel (1797) in the Peerage of Ireland, of Viscount Clancarty (1823) and Baron Trench (1815) in the Peerage of the United Kingdom and of Marquess van Heusden (1815) in the Peerage of The Netherlands. As Viscount Clancarty, the Earls sat in the House of Lords until 1999, when the House of Lords Act was passed.

The family seat is Garbally Castle , in County Galway, Ireland.

Viscounts Muskerry (1628)

• Charles MacCarty, 1st Viscount Muskerry (d. 1640)
• Donough MacCarty, 2nd Viscount Muskerry (1594-1665) (became Earl of Clancarty in 1658)

Earls of Clancarty, First Creation (1658)

• Donough MacCarty, 1st Earl of Clancarty (1594-1665)
• Charles MacCarty, 2nd Earl of Clancarty (d. 1666)
• Callaghan MacCarty, 3rd Earl of Clancarty (d. 1676)
• Donough MacCarty, 4th Earl of Clancarty (1668-1734) (forfeit 1690)

Earls of Clancarty, Second Creation (1803)

• William Power Keating Trench, 1st Earl of Clancarty (1741-1805)
• Richard Le Poer Trench, 2nd Earl of Clancarty (1767-1837), elected a Representative Peer in 1808
• William Thomas Le Poer Trench, 3rd Earl of Clancarty (1803-1872)
• Richard Somerset Le Poer Trench, 4th Earl of Clancarty (1834-1891)
• William Frederick Le Poer Trench, 5th Earl of Clancarty (1868-1929)
• Richard Frederick John Donough Le Poer Trench, 6th Earl of Clancarty (1891-1975)
• Grenville Sydney Rocheforte, 7th Earl of Clancarty (1902-1975)
• William Francis Brinsley Le Poer Trench, 8th Earl of Clancarty (1911-1995)
• Nicholas Power Richard Le Poer Trench, 9th Earl of Clancarty (b.1952)