The body was found in the passenger side of the minivan in the city's Englewood neighborhood Wednesday night, police said. It was recovered near the 5900-block of South Parnell Avenue at about 10:45 p.m.
The Cook County Medical Examiner's Office released an autopsy Thursday that determined the man's death to be a homicide.
The man's death and the fire are under investigation. The man hasn't yet been identified, police said.
Further details on the incident were not immediately available.