Firefighters tackled the fire on Princes Road just before 3am today (October 22).
Part of a four roomed flat on the first floor was damaged by the fire.
Ten people left the building before the Brigade arrived.
Firefighters led a further 13 people to safety from the second floor.
One man was taken to hospital by the London Ambulance Service.
The fire was extinguished by 4.46am.
Five fire engines and around 35 firefighters from Woodside, Croydon, Norbury and surrounding fire stations were sent to the scene.
The cause of the fire is under investigation.
A spokesperson for the London Fire Brigade said: “Five fire engines and around 35 firefighters tackled a fire at a block of flats on Prince Road in South Norwood.
“Part of a four roomed flat on the first floor was damaged by the fire.
“Ten people left the building before the Brigade arrived.
“Firefighters led a further 13 people to safety from the second floor.
“One man was taken to hospital by London Ambulance Service.
“Control Officers took the first of two calls at 0254 and mobilised crews from Woodside, Croydon, Norbury and surrounding fire stations to the scene.
“The fire was extinguished by 0446.
“The cause of the fire is under investigation.”
