Emergency crews responded to a multi-vehicle collision on the northbound Don Valley Parkway on Saturday afternoon.
Toronto police say the crash happened just after 3 p.m. near the Prince Edward Viaduct.
One vehicle flipped on its roof.
Paramedics say at least one person was transported to a hospital with minor injuries.
The left and centre lanes of the northbound DVP were obstructed for more than several hours and reopened around 7 p.m.
No other injuries were reported.