Sea World officials said Friday that Nanuq died Thursday, but the cause of the animal's death won't be determined until a post mortem.
The beluga's jaw was fractured during an encounter with two other whales that were part of a compatible social group.
The whale was estimated to be 31 or 32 years old and was originally from the Western Hudson Bay population of belugas.
The aquarium said it was "deeply saddened by the passing of Nanuq."
The beluga was transferred from Vancouver to SeaWorld in 1997.
In 1995, Nanuq sired a daughter, Qila, at the Vancouver Aquarium. Qila remains at the aquarium, contributing to education and conservation efforts.