The demography of Australia covers basic statistics, most populous cities, ethnicity and religion. The population of Australia is estimated to be 24,330,400 as of 15 January 2017. Australia is the 52nd most populous country in the world and the most populous Oceanian country. Its population is concentrated mainly in urban areas and is expected to exceed 28 million by 2030.
Australia's population has grown from an estimated population of between 300,000 and 1,000,000 at the time of British settlement in 1788 due to numerous waves of immigration during the period since. Also due to immigration, the European component of the population is declining as a percentage.
Australia has an average population density of fewer than three persons per square kilometre of total land area. With 89.01% of its population living in urban areas, Australia is one of the world's most urbanised countries. The life expectancy of Australia in 1999–2001 was 79.7 years, among the highest in the world.
The earliest accepted timeline for the first arrivals of indigenous Australians to the continent of Australia places this human migration to at least 40,000 years ago.
These first inhabitants of Australia were originally hunter-gatherers, who over the course of many succeeding generations diversified widely throughout the continent and its nearby islands. Although their technical culture remained static—depending on wood, bone, and stone tools and weapons—their spiritual and social life was highly complex. Most spoke several languages, and confederacies sometimes linked widely scattered tribal groups. Aboriginal population density ranged from approximately one person per 3 km2 (1 sq mi) along the coasts to one person per 90 km2 (35 sq mi) in the arid interior. Food procurement was usually a matter for the nuclear family, requiring an estimated 3 days of work per week. There was little large game, and outside of some communities in the more fertile south-east, they had no agriculture.
Dutch navigators landed on the coasts of modern Western Australia and Queensland several times during the 17th century. Captain James Cook claimed the east coast for Great Britain in 1770, the west coast was later settled by Britain also. At that time, the indigenous population was estimated to have been between 315,000 and 750,000, divided into as many as 500 tribes speaking many different languages. In the 2011 census, 495,757 respondents declared they were Aboriginal, 31,407 declared they were Torres Strait Islander, and a further 21,206 declared they were both Aboriginal and Torres Strait Islanders.