Six fire engines and around 40 firefighters were called to a flat fire on Woodville Road in Thornton Heath.
Part of two three-roomed flats on the first and third floors of the building were damaged by fire. A shed, a storage box and surrounding fencing and decking at the rear of a first floor flat were destroyed by the blaze. A small part of the exterior of the building was also damaged by fire.
Firefighters wearing breathing apparatus assisted one woman from a flat on the third floor to safety who was assessed on scene by London Ambulance Service crews. Around 20 people left the building before the Brigade arrived and a further 55 people left a neighbouring leisure centre. There were no reports of any injuries.
The Brigade's 999 Control Officers took 29 calls to the blaze.
Station Commander Matt Williams, who was at the scene, said: “Crews worked extremely hard to quickly bring the fire under control and stop it from spreading to the rest of the building.
“We’d like to remind residents of the importance of having working smoke alarms fitted inside your property. Make sure you also test them at least once a week.”
The Brigade was called at 1816 and the fire was under control by 1933. Fire crews from Norbury, Croydon, Mitcham and surrounding fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.