Crews were called to Royal Coach Lane and found the RV was fully engulfed when they arrived, according to Montgomery County Fire Marshal's Office investigator Trey Baxter.
The man's body was found in the kitchen area of the RV as firefighters finished dousing the flames, Baxter said.
The identity of the victim, a 51-year-old man, was not immediately released, though authorities believe he was the RV's owner.
An autopsy was ordered to determine his exact cause of death.
Investigators were still looking into how the fire started.