Four fire engines and around 25 firefighters tackled a fire at a block on flats on Brondesbury Park in Kilburn.
A three-roomed flat on the ground floor of the three-storey building was mostly damaged by fire. One adult man and one adult woman were led to safety from the property by firefighters before being taken to hospital by London Ambulance Service.
The Brigade was called at 1743 and the fire was under control by 1846. Crews from Willlesden, West Hampstead and Paddington fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and Metropolitan Police Service.