MacGillycuddy's Reeks (Irish: Na Cruacha Dubha, meaning "the black stacks") is a mountain range in County Kerry, Republic of Ireland. Stretching slightly over 19 km (12 mi), it includes the highest peaks in Ireland and the only peaks on the island that are over 1,000 metres (3,300 ft). The highest of these is Corrán Tuathail or Carrauntoohil (1,038 m), followed by Binn Chaorach (1,010 m) and Cathair na Féinne (1,001 m). The range also includes many other Hewitts (peaks of over 2,000 ft). The mountains, part of the Armorican Highlands, are of glacial-carved sandstone and are on the Iveragh Peninsula near the Lakes of Killarney.
The name of the range dates to the 18th century. It is derived from the family or clan name Mac Giolla Mochuda (anglicised MacGillycuddy) who are a sept of the O'Sullivan's. The clan chief, McGillycuddy of the Reeks, owned land in this part of Munster for a long time prior, and continued to do so until the end of the 20th century. The word reek is a Hiberno-English version of the English word rick, meaning a stack.
"MacGillycuddy's Reeks" is also the name of a song on Warren Zevon's album My Ride's Here. The song is set on the Iveragh Peninsula and also mentions the "Killarney shore" and Innisfallen. It was co-written by Ulster poet Paul Muldoon.