Four fire engines and 21 firefighters and officers were called to a flat fire on Wolverton Avenue in Kingston Upon Thames.
A flat on the top floor of a six storey block was severely damaged by the blaze.
The Brigade was called at 1235 and the fire was under control by 1310. Fire crews from Kingston, Surbiton, New Malden and Wimbledon fire stations are attending the scene. The cause of the fire is under investigation.