Four fire engines and around 25 firefighters tackled a fire at a residential block of flats on Matthew Parker Street in Westminster.
A four-roomed flat on the fifth floor of the six-storey building was partially damaged by fire. One infant suffering smoke inhalation was taken to hospital by London Ambulance Service.
The Brigade's 999 Control Officers received a call to this incident at 0618 and mobilised crews from Lambeth, Soho and Chelsea fire stations to the scene. The fire was under control by 0721.
The cause of the fire is under investigation.