Dirk Hartog Island is an island off the Gascoyne coast of Western Australia, within the Shark Bay World Heritage Area. It is about 80 kilometres long and between 3 and 15 kilometres wide and is Western Australia's largest and most western island. It covers an area of 620 square kilometres and is approximately 850 kilometres north of Perth.

Western Australia is a state of Australia occupying the western third of the land area of Australia, excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. With a total land area of 2,527,013 square kilometres (975,685 sq mi), Western Australia is Australia's largest state as well as the second-largest subdivision of any country on Earth, surpassed only by the Sakha Republic in eastern Russia. As of 2021, the state has 2.76 million inhabitants—11 percent of the national total. The vast majority live in the south-west corner; 79 percent of the population lives in the Perth area, leaving the remainder of the state sparsely populated.