Four fire engines and around 20 firefighters were called to a fire at a block of flats in Bagshot Street, Walworth.
Part of a maisonette on the first floor of the block was damaged by fire.
The Brigade was called at 0836 and the fire was under control at 0915. Fire crews from Old Kent Road, Dockhead, New Cross and Dowgate fire stations attended the scene.
The cause of the fire is under investigation.