It was after he left the top of a blue ski slope that Ulliel collided with another skier and both fell to the ground, according to a statement from the prosecutor's office in Albertsville, CNN reports.
The other skier escaped injury.
When the emergency team arrived at the scene, Ulliel lay unconscious in the snow, according to the statement.
He was taken by helicopter to the nearby hospital where his death was announced on Wednesday afternoon.
A forensic investigation has been launched with investigators from the Alps Security Police.
Career
Ulliel was praised for his portrayal of the French fashion designer Yves Saint Laurent in the biography "Saint Laurent" in 2014. He then won a César, France's equivalent of Oscar, for best male lead in the Xavier Dolan film "It's Only the End of the World" .