Mount Defiant is an 8,348-foot (2,544 m) elevation glaciated summit located 32 mi (51 km) northwest of Valdez in the Chugach Mountains of the U.S. state of Alaska.

This remote mountain is situated 2.5 mi (4 km) east-northeast of Columbia Peak, 6.5 mi (10 km) south of Mount Einstein, near the head of Columbia Glacier's Second Branch, on land managed by Chugach National Forest.

Mount Defiant was named in 1957 by members of the Chugach Mountains Expedition which was sponsored by the Arctic Institute of North America, because the rugged ice-covered peak defied all their attempts to find a route to the summit.

[4] Weather systems coming off the Gulf of Alaska are forced upwards by the Chugach Mountains (orographic lift), causing heavy precipitation in the form of rainfall and snowfall.

The months May through June offer the most favorable weather for climbing or viewing.