Four fire engines and around 25 firefighters tackled a fire at a restaurant with offices above on Charlotte Street in Fitzrovia.
Part of the fourth floor and the roof of the building was damaged by fire. There were no reports of any injuries.
The Brigade was called at 0206 and the fire was under control by 0407. Fire crews from Euston, Paddington, Soho and Islington fire stations attended the scene.
The fire is believed to have been accidental.