The London Fire Brigade said 20 fire engines carrying around 125 firefighters were scrambled to the blaze in Marylebone just before 3pm on Friday.
A fire service spokesperson said: “There is a fire in ducting which leads from the ground floor to the roof of the four storey hotel with a restaurant on the ground floor.
Footage on social media showed firefighters seeking to extinguish a vast blaze at the Chiltern Firehouse – a luxury hotel housed in a former fire station dating back to the 1880s.
Around 100 people evacuated the building before the emergency services arrived, according to the fire service, which said the cause of the blaze was not yet known.
Originally built in 1889, the building historically served as the Marylebone Fire Station and is now owned by American hotelier Andre Balazs, who also runs the Chateau Marmont in Los Angeles.
