The Titanic actress was staying at Sir Richard Branson's Caribbean home with her children and her boyfriend Louis Dowler when a blaze broke out during a tropical storm, the AP reports.
Winslet and her family escaped unscathed, as did 16 other guests that were staying at the eight-bedroom Great House on the British businessman's private island.
Branson revealed that the house was "completely destroyed" by the fire.
The cause of the fire remains unknown, though it is thought to have started due to lightning from the storm.
In July, Winslet was nominated for an Emmy for 'Outstanding Lead Actress in a Miniseries or a Movie'.
The actress reunited with Dowler in June when the two were spotted together in New York City.
Watch Kate Winslet in the trailer for Carnage below: