Garnedd Ugain, often referred to as "Crib-y-Ddysgl", is a mountain in Wales that forms part of the Snowdon Horseshoe. It is the second highest peak in Wales, and lies just under one kilometre north of Snowdon itself.
Both Garnedd Ugain and Crib-y-Ddysgl appear on the Ordnance Survey's maps of the area. The name Crib-y-Ddysgl refers to the east ridge  whilst the summit is Garnedd or Carnedd Ugain.
Crib-y-Ddysgl (meaning "ridge of the dish" in Welsh) is the name used by Alan Dawson for the peak's listing as a Hewitt.
The web pages of the Welsh Mountaineering Club suggest that the name could also be a corruption of "Carnedd Wgon", and so named after the prince Wgon sung of by Dafydd ap Gwilym or possibly after the 13th-century poet Gwgon Brydydd.