Four fire engines and around 25 firefighters were called to a fire at a house on Northborough Road in Pollards Hill.
Most of the first floor of a terraced house was damaged by the blaze. One man and one woman left the building before the Brigade arrived. They were taken to hospital by London Ambulance Service crews suffering with smoke inhalation.
The Brigade was called at 1108 and the fire was under control by 1226. Fire crews from Norbury, Mitcham, West Norwood and Croydon fire stations are at the scene.
The cause of the fire is under investigation.