Four fire engines and around 25 firefighters tackled a fire on St Peter's Road, Croydon.
A ground floor studio flat, in a block of five floors, was heavily damaged by the fire. A man was rescued from the building by firefighters, before being removed to hospital by the London Ambulance Service. There are no reports of any further injuries.
The Brigade was first called about the incident at 2359, and crews had the fire under control by 0059. Firefighters from Croydon, Woodside, Purley and Addington fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and Metropolitan Police Service.