Earthquakes Canada, the federal agency that monitors the natural phenomenon across the country, said the quake hit just after 6 p.m. Wednesday local time about 13 kilometres east of the tourism community of Tofino, B.C.
The agency advised residents that no tsunami was expected and there were no reports of damage.
The United States Geological Survey placed the quake's depth at 24 kilometres.
Tofino Mayor Josie Osborne said the quake was the strongest she has felt in the community and it lasted about one or two seconds.
"It's a really good reminder that we need to be prepared," she said.
Local resident Dave LeBlanc said the earthquake sounded like an explosion. He said he experienced the rumbling like a sound wave, as it got closer.
"And then it just started shaking like crazy," he said, noting it lasted about five or six seconds at the most.
He said his residence wasn't damaged and there was no power flicker.
Jeff Mikus said he was making dinner when he heard what sounded like an explosion or the impact of somebody driving into his house.
"You barely even felt the shaking. It was more of just a rumble and then the whole house just shook and then that was it," he said.
When it was over, many of his neighbours were outside to try and find out what happened, he said.
Residents of Tofino and Ucluelet also responded to a reporter's questions on Facebook.
Tofino's Camilla Thorogood said a big platter fell off her kitchen shelf and shattered, Lynda Kaye said her cat was hiding under its bed, and Brad Dusseault said the big cedar beams running through his home creaked like he had never heard or felt in three decades.
The quake was felt in nearby Ucluelet where Judy Gray said items fell and broke in the upstairs of her home.
"It felt like two quakes seconds apart," she said. "Little then bigger."
Osborne said the standard for preparedness is for locals to have an earthquake kit that can get them through three days, but some residents are beginning to talk about being prepared for even longer.
"With the kind of tourism economy that we have, and the visitors that we have in the summer it's not just about keeping ourselves prepared but all of the people that might be visiting Tofino," she said.
Earthquakes are common off the B.C. coast, where the Juan de Fuca tectonic plate meets the Pacific tectonic plate, but few are large enough to be felt by people.
— By Keven Drews in Vancouver with files from CKAY