Volunteer firefighters in Lantzville discovered the body after dousing the blaze early Tuesday evening.
They say the blaze began in the garage at around 6:30 p.m., and spread to the house.
No else was in the home at the time.
Members of Nanaimo RCMP's serious crime unit have taken over the investigation while the victim is identified and family are contacted.
A cause of the fire is being investigated.