Six fire engines and around 40 firefighters were called to a fire at a restaurant with flats above on Berkeley Street in Mayfair.
Crews tackled a fire in the chimney from the ground to the sixth floor of the building. There were no reports of any injuries.
Sub Officer Paul Restell, who was at the scene, said: “The fire had spread through the chimney and was visible at roof level and producing heavy smoke.
“Everyone was out of the building before the Brigade arrived.
“Firefighters worked swiftly to bring the fire under control and carried out a systematic search of the building to ensure that there were no remaining hot spots.”
The Brigade’s 999 Control Officers took 11 calls to the blaze.
The Brigade was called at 0146 and the fire was under control by 0304. Fire crews from Soho, Chelsea, Kensington, Lambeth, Euston and Dowgate fire stations attended the scene.
The cause of the fire is under investigation.