Four fire engines and around 25 firefighters and officers were called to a fire at a house in Montpelier Square, Knightsbridge.
A large part of the third floor and half of the second floor of the property were damaged by fire.
The Brigade was called at 1353 and the fire was under control at 1531. Fire crews from Fulham, Battersea, Soho and North Kensington fire stations attended the scene.
The cause of the fire is under investigation.