| MacCarthy | |
| Native Name: | Mac Cárthaigh |
| Native Name Lang: | ga |
| Coat Of Arms: | MacCarthy.png |
| Coat Of Arms Size: | 150px |
| Alt: | A shield of arms showing a red stag on a white ground |
| Parent Family: | MacCarthy Mor |
| Founded: | 1353 |
| Founder: | Dermot, 1st Lord of Muskerry |
| Final Ruler: | Donogh, 4th Earl of Clancarty |
| Titles: | Lord of Muskerry, Viscount Muskerry, and Earl of Clancarty |
| Estate: | Muskerry |
The MacCarthy dynasty of Muskerry is a tacksman branch of the MacCarthy Mor dynasty, the Kings of Desmond.
The MacCarthy of Muskerry are a cadet branch of the MacCarthy Mor, Kings of Desmond. This cadet branch was founded by Dermot MacCarthy, 1st Lord of Muskerry, second son of Cormac MacCarthy Mor, King of Desmond, who was in 1353 created Lord of Muskerry by the English. This title's position is unclear. Cormac Laidir MacCarthy, 9th Lord of Muskerry was called Dominus and F. Dermot's descendant Cormac Oge MacCarthy, 17th Lord of Muskerry, was in 1628 created Charles MacCarthy, 1st Viscount Muskerry, and his son, the 2nd Viscount Muskerry, was in 1658 created Donough MacCarty, 1st Earl of Clancarty.
The family's ancestral lands of were situated along the River Lee in the baronies of Muskerry West and Muskerry East, in central County Cork west of the City of Cork.
Kilcrea Friary, built by Cormac Laidir MacCarthy, 9th Lord of Muskerry
The Blarney Stone passed from MacCarthy hands during the Williamite wars. Following the forfeiture by Donogh McCarthy, 4th Earl of Clancarthy, the castle property passed to the Hollow Sword Blade Company who subsequently sold it to Sir James St. John Jefferyes, Governor of Cork in 1688.
Donough MacCarthy, 4th Earl of Clancarty fought in the Williamite War in Ireland for James II of England against William III of England. He was attainted at the defeat in 1691 and the MacCarthys of Muskerry lost the noble titles of Earl of Clancarty, Viscount Muskerry, and Baron Blarney.
The titles of Mountcashel and Baron Castleinch, of the (1689 creation, went extinct with the death of Justin MacCarthy in 1694. At that date the MacCarthys of Muskerry had therefore lost all their noble titles in the peerage of Ireland.