Firefighters wearing breathing apparatus found the woman unconscious on the sofa of her fourth floor flat and brought her out of the property.
Station Commander Alan Brand, who was at the scene, said: “Firefighters worked incredibly hard and fast to rescue the woman and deal with the small fire on the fourth floor. They administered emergency care to the woman before the ambulance arrived. She was taken to hospital by London Ambulance Service crews.”
Part of the flat was damaged by the fire. There was smoke damage throughout the property.
There was a working smoke alarm in the flat which was sounding. The fire was discovered by a passer-by who called 999.
The cause of the fire is believed to be the unsafe disposal of a cigarette.
The Brigade was called at 4.14pm and the fire was under control by4.46pm Fire crews from Soho, Islington, Lambeth and Bethnal Green fire stations attended the scene.