The Ontario Provincial Police say the crash occurred shortly after 8 a.m., on Highway 89, near the 2nd Concession of the Township of Adjala-Tosorontio.
When police arrived at the scene, the Toyota "was fully engulfed in flames."
The driver in the passenger vehicle was fatally injured in the crash, while the dump truck driver — a 59-year-old man from Dundalk, Ont., — suffered minor injuries.
By Thursday afternoon, police determined that the dump truck was eastbound on Highway 89 and the Toyota was westbound at the time of the collision.
According to police, the Toyota “veered into the path of the truck and they collided.”
Police say the dump truck driver made efforts to avoid the crash.
The deceased Toyota driver has still not been identified.
The collision remains under investigation.
The Ministry of Environment was also at the crash scene on Thursday afternoon, dealing with diesel that spilled as a result of the collision.