The federal agency that monitors earthquakes revised its original report, saying it registered a 5.1-magnitude temblor with an epicenter located about 21 kilometers (13 miles) northeast of Shawville, Quebec, about an hour's drive outside Ottawa.
It was felt as far west as Toronto, Canada's largest city, but no damage was immediately reported.
Twitter erupted with reports of buildings shaking in Ottawa for several seconds. Ontario's premier, who lives in Toronto, tweeted that her house was shaking.
Ontario Provincial Police in Arnprior, Ontario, not far from the epicenter, say they have received no reports of damage.
The original report said a 4.8-magnitude quake was centered near the town of Braeside, Ontario.
