Six fire engines and around 40 firefighters were called to a fire at a disused church on Woodgrange Road in Forest Gate.
Part of the ground floor of the church was damaged by fire. There were no reports of any injuries.
The Brigade was called at 0146 and the fire was under control by 0321. Fire crews from Stratford, Plaistow, Leytonstone and East Ham fire stations attended the scene.
The cause of the fire has been recorded as undetermined.