The hotel on Lugley Street has been evacuated as crews from Newport and Ryde work to extinguish the fire.
3 appliances are on scene alongside an aerial ladder platform and the Incident Command Unit, although the situation is understood to be under control.
The alarm was raised at around 16:25.
The Isle of Wight Ambulance Service are also on scene.
UPDATE @ 17:22 – The fire has been extinguished and positive pressure ventilation is now being used to rid the building of smoke.
The cause of the fire is yet to be disclosed.
Crews are starting to stand down from the incident but 2 appliances remain on scene.
UPDATE @ 17:45 – 1 person has been conveyed to St Mary’s Hospital as a result of the fire, which broke out on the ground floor.