Four fire engines and around 25 firefighters were called to a fire at a waste transfer building on Hallowfield Way in Mitcham.
Around three tonnes of general domestic waste was alight. There were no reports of any injuries.
The Brigade was called at 0539 and the fire was under control by 0708. Fire crews from Mitcham, Sutton and Wimbledon fire stations attended the scene.
The cause of the fire is under investigation.