Four fire engines and around 25 firefighters have been called to a fire at a flat on Jackson Road in Islington.
Part of a three-roomed flat on the first floor of a three-storey terraced building is alight.
The Brigade was called at 1021. Fire crews from Kentish Town, Islington and Stoke Newington fire stations are at the scene.
The cause of the fire is not known at this stage.