The (Montreal) Gazette reported the fire broke out at the Olymel bacon production facility about 3 a.m. and firefighters were still at the scene at noon.
The Canadian Broadcasting Corp. reported about 50 firefighters were called in to extinguish the blaze.
The network said the fire was reported by a security guard, who was the only person at the plant when the fire ignited.
No injuries were reported and the cause of the fire had not been determined.
The plant employees 180-200 people.