Carnac Island is an A Class nature reserve approximately 10 kilometres south west of Fremantle, Western Australia.

In 1803 French explorer Louis de Freycinet, captian of the Casuarina named the island Ille Pele (Bald Island). It was also nown as Ille Levilian and later Pulo Carnac. In 1827, James Stirling changed its name to Carnac Island in honour of John Rivett Carnac, an officer of his ship HMS Success

The island is home to Australian Sea Lions, Bottlenose Dolphins and a large range of marine bird life. It is particularly noted for the abundance of snakes, particularly Dugites which live on the island. For this reason, very few people venture onto the island.