Four fire engines and around 25 firefighters were called to a fire at a school on Harbury Road in Carlshalton.
A roof on the first floor level of a school complex was damaged by fire.
The Brigade was called at 0658 and the incident was over by 0818. Fire crews from Wallington, Sutton, Mitcham and Croydon fire stations were attending the scene.
The cause of the fire is under investigation.