The U.S. Geological Survey said it struck about 230 miles (370 kilometers) northwest of Juneau, Alaska, and 155 miles (250 kilometers) west of Whitehorse, Yukon.
In Whitehorse, Royal Canadian Mounted Police Sgt. Calista MacLeod said the detachment received two 911 calls about the earthquake.
"It definitely was felt," MacLeod said. "There are a lot of people on social media, people felt it."
She said there were no reports of damage or injury.
The quake was also about 56 miles (91 kilometers) from Yakutat, Alaska, which the USGS said has a population of 662.
It struck at a depth of about 6 miles (10 kilometers) and was followed by multiple smaller aftershocks.