The name "Australia" is derived from the Latin Australis, meaning "of the South". Legends of an "unknown land of the south" dating back to Roman times were commonplace in medieval geography, but were based on no actual knowledge of the continent. Australia consists of six states, two major mainland territories, and other minor territories. The states are New South Wales, Queensland, South Australia, Tasmania, Victoria and Western Australia. The two major mainland territories are the Northern Territory and the Australian Capital Territory. Australia's 7,617,930 square kilometres (2,941,299 sq. mi) landmass is on the Indo-Australian Plate. Surrounded by the Indian, Southern and Pacific oceans, Australia is separated from Asia by the Arafura and Timor seas.

The Great Barrier Reef, the world's largest coral reef, and lies a short distance off the north-east coast and extends for over 2,000 kilometres (1,250 mi). Mount Augustus claimed to be the world's largest monolith, is located in Western Australia. At 2,228 metres (7,310 ft), Mount Kosciuszko on the Great Dividing Range is the highest mountain on the Australian mainland, although Mawson Peak on the remote Australian territory of Heard Island is taller at 2,745 metres (9,006 ft).

By far the largest part of Australia is desert or semi-arid. Australia is the flattest continent, has the oldest and least fertile soils, and is the driest inhabited continent. Only the south-east and south-west corners of the continent have a temperate climate. Most of the population lives along the temperate south-eastern coastline. The landscapes of the northern part of the country, with a tropical climate, consist of rainforest, woodland, grassland, mangrove swamps and desert. The climate is significantly influenced by ocean currents, including the El Niño southern oscillation, which is correlated with periodic drought, and the seasonal tropical low pressure system that produces cyclones in northern Australia.