Four fire engines and around 25 firefighters dealt with a flat fire above a shop on Kilburn High Road.
Part of the first floor flat was damaged by the blaze. There were no reports of any injuries.
The Brigade was called at 1016 and the fire was under control by 1102. Fire crews from West Hampstead, Willesden and Paddington fire stations were at the scene. The cause of the fire is under investigation.