Grand Cornier, Mountain peak in Valais, Switzerland

Grand Cornier is a 3,962 m mountain in the Pennine Alps of Valais, Switzerland, standing 2 km north of the Dent Blanche. Its normal route leaves the Cabane de Moiry near Grimentz and crosses the crevassed Moiry Glacier southward to a 3,843 m fore-summit, then climbs the northwest ridge (grade III–IV) to the top.

The summit was first reached on June 16, 1865, by Edward Whymper's climbing party. This ascent occurred during the era when mountaineers were systematically exploring and climbing the high Alpine peaks.

The name Grand Cornier comes from the Franco-Provençal patois of Valais, in which "cornier" designates a corner or a projecting rocky point, a shape the mountain's ridges give it when seen from the Ferpècle valley. The Borgne de Ferpècle, the stream that drains the valley below, rises at the foot of the mountain between the Ferpècle and Mont-Miné glaciers.

The climb typically starts from either the Mountet hut or the Moiry hut, both serving as resting places near the base. Summer months provide the best conditions for the ascent, with more stable weather and less ice.

The mountain rises 2 km north of the Dent Blanche, and the Borgne de Ferpècle has its source at its foot, fed by the Ferpècle and Mont-Miné glaciers. The pre-summit at 3,843 m is usually the end point of a ski ascent.