Peel Regional Police said the victim's body was found around 9:24 p.m. near Airport Road and Victory Crescent. Paramedics pronounced the man dead at the scene.
Police haven't identified the victim at this time, saying the person's injuries were too extensive.
The truck driver is cooperating with the investigation, police said, but said it's too early to say if charges will be laid in connection with the collision.
Anyone who witnessed the incident is asked to contact police.