A fire broke out in the roof of The George in Rye hotel in Rye High Street just after 4.30am.
At its height there were eight fire engines and 40 firefighters at the scene.
The cause of the fire has not yet been confirmed.
A spokesman for The George in Rye said: "We are overwhelmed by the incredible support received from the local community following a fire at the hotel in the early hours of this morning.
"East Sussex Fire Service were on site within five minutes and everyone was evacuated safely and nobody was hurt.
"We'd like to thank the fire service and our staff for their outstanding efforts.
"We're devastated our beautiful building has been damaged and work starts today to get everything up and running as soon as possible.
"We'd like to thank our wonderful guests who have been amazing in their response."