The McGillycuddy of the Reeks (Irish: Mac Giolla Mochuda) is one of the hereditary chiefs of the name of Ireland. The current family head is Donough McGillycuddy, who lives in Himeville, KwaZulu-Natal, South Africa.
The McGillycuddy of the Reeks is a direct descendant of Mogh Nuaghad, King of Munster, who ruled around 125 AD, and his son, the celebrated Prince Olioll Olum (d. 234), the 43rd direct descendant of the Spanish warrior Milesius, (1284 BC).
The name McGillycuddy originates from when O'Sullivan Mór sent his trusted son, Mac Giolla, to be educated under the tutelage of Saint Mochuda at Lismore. He hence became known as Mac Giolla Mochuda, which has been anglicised into McGillycuddy.
The current chieftain, Donough McGillycuddy, was born at Bishopscourt, Straffan, County Kildare, on 17 December 1939. His father, Dermot, a solicitor, joined the Royal Air Force Volunteer Reserve during the Battle of Britain, rising to the rank of Squadron Leader. He was a keen sportsman: he was oarsman at Eton College and Trinity College, Dublin and played rugby. He became well known in Irish legal and sporting circles and as manager of Punchestown race course. The Chieftain's mother was the fourth daughter of an eminent Irish bloodstock breeder.
McGillycuddy was principally educated at Eton, and briefly at Neuchâtel University. He ran and rowed at Eton before joining the Irish Guards in 1958, in which he served until 1962. He later spent a year at Le Pin-au-Haras, headquarters of the French National Stud in Normandy, studying bloodstock breeding and equitation. He married Wendy O'Connor Don Spencer at Winwick, Northamptonshire on 4 April 1964. Her father was the late George Spencer, JP, FRS, who married Susan Ballam, born at Manorhamilton, County Leitrim, in 1931. Wendy died at Himeville, South Africa, on 4 September 2013.