A baby boy suffered the effects of smoke inhalation and was taken to hospital after a fire broke out in the underground car park below St Luke's Court in Tooley Street.
Around a dozen residents were evacuated from the building when the fire broke out. The London Fire Brigade was called just after 10.30pm and the blaze was under control by 0.45am.
Magdalen Street, behind St Luke's Court, was shut so that firefighters could draw water from a nearby hydrant.
The cause of the fire is under investigation.