Six fire engines and 35 firefighters and officers were called to a fire at a shop with flats above in Newport Court in Soho.
Part of the first floor communal landing was damaged by fire. Approximately 20 people left the building before the arrival of the Brigade.
One woman suffering from smoke inhalation was led to safety via an internal staircase by crews wearing breathing apparatus before being treated at the scene by London Ambulance Service crews.
The Brigade was called at 2159 and the fire was under control at 2342. Fire crews from Soho, Dowgate, Islington, Kentish Town, Euston and Old Kent Road fire stations attended the scene.
The cause of the fire is under investigation.