Three fire engines and around 15 firefighters were called to a fire at a block of sheltered accommodation on Penfold Street in Marylebone.
There had been a fire in a room on the first floor, which was out when the Brigade arrived. A man was found in the room and was taken to hospital, where he sadly later died.
The Brigade was called at 1456 and the incident was over for firefighters by 1524. Fire crews from Paddington and Euston fire stations were at the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.