Ten fire engines and around 70 firefighters were called to a fire in a two-storey derelict warehouse on the North Circular Road in Neasden overnight.
The whole of the building was damaged by the fire.
London Fire Brigade Urban Search and Rescue crews used specialist equipment and found the body of a person inside the property. They have sadly been pronounced dead at the scene.
Seventeen people were evacuated from neighbouring properties as a precaution.
The Brigade was called at 0238 and the fire was under control at 0622. Fire crews from Willesden, Park Royal, Hendon, Wembley, Stanmore and West Hampstead fire stations attended the scene.
The cause of the fire is under investigation.