His family told news agency AFP he died on Wednesday following a skiing accident in the Alps.
Ulliel, one of France's best-known actors, has appeared in It's Only the End of the World and Saint Laurent, the biopic of the French fashion designer.
The actor was skiing in the Savoie region on Tuesday when he collided with another person.
He suffered severe brain trauma and was airlifted to a hospital in Grenoble, where he died the next day.
The other skier was not hospitalised and an investigation is now under way.
