Four fire engines and around 25 firefighters were called to a flat fire on Kensington High Street.
Most of a flat on the sixth floor of the seven-storey building was damaged by the fire. Firefighters wearing breathing apparatus found a woman in the hallway. She was taken to hospital by London Ambulance Service crews, where she sadly later died.
The Brigade was called at 1343 and the fire was under control by 1503. Fire crews from Hammersmith, Fulham, Chelsea and Chiswick fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.