No-one was injured after the fire licked through a ground floor flat in the Agincourt Avenue area this morning.
Fire crews from station across Belfast were called to the scene at around 11.32 am.
An hour later the fire was brought under control.
Police later confirmed that a man had been arrested at the scene and was being held on suspicion of arson.
He is currently in custody at Musgrave PSNI station being questioned.