Emergency crews responded to a fatal crash just before noon on Friday in Enniskillen Township.
Lambton OPP, EMS, and Petrolia and North Enniskillen firefighters responded at around 11:40 a.m.
OPP Cst. Jamie Bydeley said a commercial vehicle and a passenger vehicle collided at the intersection of Courtright Line and Marthaville Road.
A 61-year-old from Petrolia was pronounced deceased at the scene.
Bydeley said no charges have been laid at this time and the investigation continues.