Crews from Elm Lane, Rivelin and Central attended the incident shortly after 7:15am, Saturday 28 October on Colley Drive, Parson Cross.
A South Yorkshire Fire and Rescue spokesman: "Firefighters wearing breathing apparatus entered the property, which was heavily smoke logged. The occupant was sadly found to have died.
"A multi-agency investigation will take place to determine the cause of the fire."
No further details on the man have been released at this time.