Bunbury is a coastal city in the Australian state of Western Australia, approximately 175 kilometres (109 mi) south of the state capital, Perth. It is the state's third most populous city after Perth and Mandurah, with a population of approximately 75,000.

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.