Four fire engines and around 25 firefighters were called to a flat fire on Albany Street in Marylebone.
Part of a flat on the second floor of a four-storey block was damaged by the fire. There were no reports of any injuries.
The Brigade was called at 1216 and the fire was under control by 1315. Fire crews from Soho, Paddington and Euston fire stations were the scene.
The cause of the fire is under investigation.