Great Whernside is a mountain in the Yorkshire Dales, England, not to be confused with the better known Whernside, some 27 kilometres (17 mi) to the west. Its summit is the highest point of the eastern flank of Wharfedale above Kettlewell. The curving escarpment above the pass between Wharfedale and Coverdale is known as Whernside, of which Great Whernside is the highest point; Little Whernside is a few kilometres to the north-east.
Great Whernside forms the watershed between Wharfedale and Nidderdale, and is on the boundary between the Yorkshire Dales National Park and Nidderdale Area of Outstanding Natural Beauty. Little Whernside forms the watershed between Coverdale and Nidderdale. The River Nidd rises on the eastern slopes of Great Whernside, above Angram Reservoir.
The summit of Great Whernside is a plateau strewn with rocks of millstone grit, from which the mountain takes its name (quern meaning "millstone").
Great Whernside is usually ascended from Kettlewell or from the pass on the minor road from Kettlewell to Coverdale. It can also be ascended by a longer route from Scar House Reservoir, some 8 kilometres (5.0 mi) away.
Until 1997 no public right of way was established to the summit of Great Whernside. In that year two public footpaths were registered, one from Kettlewell to the summit and one along the summit ridge. Following the Countryside and Rights of Way Act 2000 the whole mountain became open access land.