Kangaroo Island is Australia's third-largest island, after Tasmania and Melville Island. Situated  in the state of South Australia 112 km (70 mi) southwest of Adelaide, its closest point to the mainland is Snapper Point in Backstair Passage which is 13.5 km (8.4 mi) from the Fleurieu Peninsula.

Once occupied by Australian Aborigines, the native population disappeared after the land became an island following rising sea levels several thousand years ago. It was subsequently resettled from the early 19th century onwards, at first casually by sealers and whalers, and then as part of the colony of South Australia from 1836.

The island has several nature reserves to protect the remnants of its natural vegetation and native animals, with the largest and best-known being Flinders Chase National Park at the western end.