Rottnest Island was inhabited by Aborigines since approximately 30,000 years ago, until rising sea levels separated the island from the mainland of Western Australia approximately 7,000 years ago. The island features in Nyoongar Aboriginal mythology.
The island was identified by Dutch sailors in 1610, and the name was bestowed upon the island by the Dutch fleet captain Willem de Vlamingh in 1696. Vlamingh (or one of his crew) believed that the indigenous marsupial called a quokka was in fact a large rat ("rottnest" meaning "rat's nest" in the Dutch language).
Upon the establishment of the British colony in nearby Perth in 1829, the island was used for the next 70 years as a prison for Aboriginal convicts. It became devoted to recreational use in the 1900s, aside from a brief period of exclusive military use during World War 2. Wartime cannon batteries and camoflaged sites are still in existence at various parts of the island.
The resort island features historic buildings, and pleasant beaches (all reachable via the many cycling tracks that are the island's main mode of transport). A well-maintained wildlife preserve, Rottnest is popular with divers (the island and its surrounding reefs are littered with ship wrecks), surfers (there are several notable reef breaks at the west end of the island at Strickland Bay, Salmon Bay and Stark Bay), and recreational fishers.
The main settlement is located at Thompson's Bay, facing east towards Fremantle. Other settlements are located at Geordie Bay and Longreach. Rottnest Island is sparsely populated by permanent residents, as special permission from the Western Australian government is necessary to live on the island. A small airport for light aircraft is located near the main settlement. The Rottnest Lodge is a high quality hotel located in the centre of the settlement at Thompson's Bay.
Each year, around November, the island is inundated with school leavers and university students, who celebrate their graduation with extended bouts of binge drinking at the bar in Thompson's Bay (called the "Quokka Arms") and at rented cabins and units. In 1986, outrageous student behaviour resulted in multiple arrests and expulsions from the island, and made national news. Revelry also occurs on Rottnest Island every New Year's Eve.
The Western Australian vernacular diminutive for "Rottnest Island" is "Rotto".