The child was crossing at a four-way stop with his mother — on his way to junior kindergarten at Artesian Drive Public School, near Winston Churchill Boulevard and Highway 403 — when he was hit.
Residents say they've been complaining for years that drivers go too fast through the school zone, often using it as a shortcut to the main thoroughfare.
"People are speeding, doing 60, 70 with no regard for the children," local resident Huma Yousf told CBC News. "There should be speed breakers here."
Julien Wintony, whose daughter is in kindergarten at the school, says some drivers don't even stop at the stop signs. "I see so many people around here driving crazy around here," he said.
There are signs warning drivers to watch for children, and police say they patrol the area regularly.
The car was driven by a 78-year-old Mississauga man who was making a left-hand turn, perhaps with the morning sun in his eyes. The names of the driver and victim have not been released.
No charges have been laid. Peel Regional Police are investigating.
A makeshift memorial, a pile of flowers and teddy bears, stand by one of the stop signs where the incident occured.
Grief counsellors are at the school today, helping students and teachers cope with the loss.