10 people have been taking to hospital, including three with serious injuries.
Hydro Ottawa says more than 170,000 people were still in the dark as of 7:30 a.m., and 114,000 were affected by outages in Quebec.
Peter Kimbell, a meteorologist with the national weather agency, said the tornado overturned cars on Highway 50 in Gatineau and caused extensive damage to houses in Dunrobin. He added that workers are expected to start repairing the approximately 80 downed power lines Saturday and that some people would have their power restored in the next two days.
Canadian Prime Minister Justin Trudeau urged residents to check on neighbors who might need help.
The powerful twister caused devastation as it tore through the cities of Ottawa in Ontario and Gatineau, Quebec.
Power in the area has also been affected with around 167,000 Hydro One customers who were without electricity late Friday evening.
Anthony Di Monte, general manager of emergency and protective services, said Ottawa's building and fire services are assessing structural damage across the city. "(We) recognize the very hard circumstances that many people in our communities find themselves-some have lost their homes, other have been injured, other have loved ones in hospital, so we think of them".