Two people were taken to hospital after two deadly hit-and-run incidents on Toronto roads overnight.

A 51-year-old woman was struck while crossing Kingson Road, east of Warden Avenue shortly before midnight on Saturday, police said.

She was taken to hospital with life-threatening injuries.

Police say witnesses described a dark-coloured SUV leaving the scene.

"The vehicle fled the scene, leaving the female on the roadway," Toronto Traffic Services Sgt. Tim Burrows told reporters.

A few hours later, police say a man was rushed to hospital with serious but non life-threatening injuries after two cars collided while speeding along Yonge Street, north of Highway 401.

The cars appeared to have made contact, sending one off the road and into a pole. The other car failed to remain at the scene, police said.