There were no reports of damage or injuries.
Earthquakes Canada said the 5.7-magnitude quake hit about 6:20 am local time. The US Geological Survey reported the same magnitude and said it struck about 96 miles south of Port Hardy on Vancouver Island.
Earthquakes Canada said the quake was lightly felt across the northern part of the island.
Bonnie Overland, a resident of Port Alice on Vancouver Island, said she was awakened by the shaking but thought it was her dog scratching the bed.
"It lasted a few seconds and we absolutely felt it," she said.
There was no tsunami alert.