Pol Col Rattasak Raksalam of Thong Lor Police Station refused to identify the woman, saying she succumbed to death at Kluinamtai Hospital 1 at about 4am.
About 21 people, mostly foreigners, were injured when a blaze broke out at the fourth floor of the 15-storyed hotel at 9.50pm last night.
Fire fighters took about 30 minutes to control the blaze.