Four fire engines and 21 firefighters and officers were called to a fire at a house in Durham Street, Vauxhall.
Part of the ground floor of a mid-terraced house was damaged in the fire. One man suffering smoke inhalation was taken to hospital by London Ambulance Service crews.
The Brigade was called at 1155 and the fire was under control at 1258. Fire crews from Lambeth, Clapham, Peckham and Soho fire stations attended the scene.
The cause of the fire is under investigation by the Metropolitan Police Service.