Emergency crews were called to Markham Road near Blakemanor Boulevard at around 12:45 a.m. after a transit bus struck a pedestrian.
Police said the pedestrian had stepped off the east sidewalk of Markham Road midblock and was struck by a TTC bus travelling in the curb lane.
The man was pronounced dead at the scene.
The road was closed due to the investigation but has since reopened. TTC service has also resumed.