Hundreds of guests at the Fairmount Chateau Laurier were forced from their rooms for about half an hour Thursday night after a fire broke out in the ceiling of a sauna on the main floor.
Fire crews were called to 1 Rideau Street at about 11:40 p.m. and had the blaze under control quickly. No injuries were reported.
A masonry structure surrounding the sauna helped contain the fire, Ottawa Fire Services officials said, and damage was estimated at $12,000.
The hotel in the historic building at 91 per cent capacity at the time, and guests had to wait in the lobby while the fire was contained.
Fire officials said a light fixture in the sauna may have been the cause of the fire.