Ontario Provincial Police said the crash happened around noon on Tuesday between Winston Churchill Boulevard and Mississauga Road.
Sgt. Kerry Schmidt said transport gravel hauler rear-ended another truck hauling camper trailers. The vehicle then rear-ended a van trailer.
A 45-year-old man from Richmond Hill was pronounced dead at the scene.
Police said traffic was forced off at Winston Churchill Boulevard.
The cause of the collision is under investigation.
Authorities said the eastbound lanes reopened to traffic at 4:30 p.m.
WATCH: Aerial view of fatal crash