Squaw Valley Fire Chief Pete Bansen says the accident happened Thursday afternoon at the top of the mountain near the Granite Chief lift.
Ski patrol members administered CPR, but the skier was pronounced dead at the scene.
The victim's name was withheld pending notification of family members.
Two other skiers were killed at Squaw Valley this season.
In March, 41-year-old ski patrol member Andrew Entin died after being partially buried during avalanche control work. In December, 21-year-old Randall Davis of Tahoe City was killed when an avalanche swept him down a steep, tree-covered slope.