Fernleigh Castle is a historic house in the Sydney suburb of Rose Bay. It is listed on the Australian Register of the National Estate. The two-storey home was built on the site of a sandstone cottage built in 1874, and incorporates the original walls of that building. Castle-like in appearance, it is constructed of sandstone and features a square Norman-style tower, smaller towers with their own turrets, and castellated walls. Although it also includes wrought iron balconies similar to homes in Paddington. The house has thirty rooms and a number of stained-glass windows.