Four fire engines and around 25 firefighters were called to a fire at a school on Sandy Lane South in Wallington.
Part of a single-storey classroom was damaged by the fire. There were no reports of any injuries.
The Brigade was called at 1403 and the fire was under control by 1528. Fire crews from Wallington, Croydon and Purley fire stations were at the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.