Five fire engines and 31 firefighters and officers were called to a fire at a restaurant with flats above in City Road, Islington.
Part of the restaurant on the ground floor was damaged by the fire.
Ten people left the flats before the Brigade arrived.
Watch Manager Jason Croucher, who was at the scene, said: “A member of the public walking past the shop heard the smoke alarm and called us.
“There was thick acrid smoke when we arrived and crews worked hard to quickly bring the fire under control and stop it spreading to the flats above.”
The Brigade was called at 2226 and the fire was under control by 0051. Fire crews from Shoreditch, Dowgate, Whitechapel, Bethnal Green and Islington fire stations attended.
The cause of the fire is believed to be a fault within an industrial freezer.