Mount Cornwell is a mountain, high, standing 2miles south of Mount Washburn in Gromshin Heights along the northeast side of Newcomer Glacier in the northern part of the Sentinel Range. It surmounts lower Vicha Glacier to the east and Newcomer Glacier to the west.
The mountain was named by the Advisory Committee on Antarctic Names for Lieutenant James W. Cornwell of U.S. Navy Squadron VX-6, who was co-pilot on photographic flights over the range on 14–15 December 1959.
