Four fire engines and around 25 firefighters tackled a fire at a block of flats on Mowatt Close in Holloway.
Half of a flat split between the second and third floors was damaged by the fire. There are no reports of any injuries.
Control Officers took the first of two calls at 1248 and mobilised crews from Kentish Town, Hornsey and Islington fire stations to the scene. The fire was extinguished by 1402.
The cause of the fire is under investigation.