Cape Barren Island, officially truwana / Cape Barren Island, is a 478-square-kilometre (185 sq mi) island in Bass Strait, off the north-east coast of Tasmania, Australia. It is the second-largest island of the Furneaux Group, with the larger Flinders Island to the north, and the smaller Clarke Island to the south. The highest point on the island is Mount Munro at 715 metres (2,346 ft). Mount Munro is named after James Munro, a former convict turned sealer who, from the 1820s, lived for more than 20 years with various indigenous women on nearby Preservation Island.

Bass Strait is a strait separating the island state of Tasmania from the Australian mainland. The strait provides the most direct waterway between the Great Australian Bight and the Tasman Sea, and is also the only maritime route into the economically prominent Port Phillip Bay.