Firefighters were called at about 3 p.m. Monday by a labourer working in a nearby house in the community almost 500 kilometres north of Montreal.
Once the blaze was extinguished, three bodies were discovered inside.
Ottawa police say the suspect, identified as 35-year-old Justin Bresaw, was last seen Tuesday in the Kanata North area.
He is described as white, five-foot-seven and 153 pounds with a bald head and was last seen wearing a red long sleeve shirt, black pants, black work shoes and carrying a black backpack.
Police say Bresaw should be considered armed and dangerous and may be driving a stolen 2001 blue Honda Civic, bearing Quebec licence plate 788 JNC.
Police have not yet identified the fire victims.