Four fire engines and around 25 firefighters were called to a house fire on Camden Gardens in Thornton Heath.
Firefighters wearing breathing apparatus rescued a young man from the first floor via an internal staircase. He was taken to hospital by London Ambulance Service crews where he sadly later died.
Part of the ground and first floor of the property was damaged by fire.
The Brigade was called at 1734 and the fire was under control by 1945. Fire crews from Norbury and West Norwood fire stations attended the scene.
The cause of the fire is under investigation.