Porter Flight PD539, a Bombardier Dash 8-400, departed from Billy Bishop in downtown Toronto at 7:35 p.m. ET.
Shortly after takeoff, the twin-propeller aircraft was diverted to Pearson.
Mireille Langlois, the Radio-Canada reporter who was aboard the flight said the cabin began filling with smoke shortly before the decision to turn back to Toronto was announced.
The plane landed safely, and passengers have been unloaded and are being shuttled to a terminal aboard buses.
No representatives from Porter or the Greater Toronto Airport Authority were immediately available for comment Sunday night.
The incident was the second aboard a Porter aircraft on Sunday. Hours earlier, another Porter flight from Toronto to Washington, D.C., made an unscheduled landing in Pennsylvania after smoke was detected on board. No one was injured and the plane landed safely.
Also on HuffPost