Lee Dobson, 40, was discovered inside the property in Broomrig Court in Lincluden, Dumfries, after the smoke alarm was activated in the early hours of Tuesday.
Crews extinguished a fire in the kitchen and carried Mr Dobson outside.
A Scottish Fire and Rescue Service spokesman said: "He was taken to Dumfries and Galloway Royal Infirmary by ambulance but sadly it was later confirmed that he had died."
Police said the death was being treated as unexplained until the results of a post-mortem examination were known.
Meanwhile, three people were treated for smoke inhalation after two separate fires in Paisley and Renfrew. Fire fighters were called out at 9.35pm on Tuesday night to a fire on Fulbar Street in Renfrew.
At the same time, crews were called to a chip pan fire in Findhorn Avenue in Paisley.