The infant mortality rate in Australia, for children under the age of one year old, was 111 deaths per thousand births in 1870. This means that for all babies born in 1870, over eleven percent did not survive past their first birthday. Over the course of the next 150 years, this number has dropped significantly, reaching its lowest point ever in 2020 to three deaths per thousand births.

The child mortality rate in Australia, for children under the age of five, was 391 deaths per thousand births in 1860. This means that just under forty percent of all children born in 1860 did not make it to their fifth birthday. This number dropped drastically over the next ten years, then it remained between 150 and two hundred for the remainder of the 1800s, before dropping consistently from 1900 until today. By 2020, child mortality in Australia is expected to be approximately four deaths per thousand births.

In Australia, the crude birth rate in 1800 was 45 births per thousand people, meaning that 4.5 percent of the population had been born in that year. In the first half of the nineteenth century, Australia's crude birth rate decreased gradually, reaching just under 36 in 1850, however it then increased again over the next fifteen years, as the gold rushes brought many immigrants to the continent. After this, the crude birth rate dropped gradually until the Second World War, after the war Australia experienced another baby boom, reaching it's peak of 23 children per thousand in 1955. In the late 1970s the rate dropped rather sharply, falling from around twenty in 1970 to 15.8 in 1980, and since then the birth rate has decreased at a slower rate, and has fallen below thirteen births per thousand people in 2020.

The fertility rate of a country is the average number of children that women from that country will have throughout their reproductive years. In 1800, Australian women of childbearing age would go on to have approximately 6.5 children on average over the course of their lifetime, and this number decreased gradually to just below five in the early 1850s. Over the next ten years the fertility rate increased to 5.7 children per woman, as an influx of migrants arrived on the continent during the Australian gold rushes, however the fertility rate dropped from 1860 until 1935, when it was then just 2.2 children per woman, although there was a small baby boom after the First World War. Australia's fertility rate did rise during the global 'Baby Boom' after the Second World War, reaching 3.4 in the 1960s, but it then dropped to two children per woman in 1980, and it has plateaued just under this number until today.

Life expectancy in Australia was just below 35 in the year 1870, and over the course of the next 150 years, it is expected to have increased to 83.2 by the year 2020. Although life expectancy has generally increased throughout Australia's history, there were several times where the rate deviated from its previous trajectory. the most noticeable changes were between 1890 and 1920. This period included Australia's Independence movement, the implementation of the 'White Australia' policy, the First World War and Spanish Flu epidemic, all of which impacted the demographics of Australia.

Humans have been living on the continent of Australia (name derived from "Terra Australis"; Latin for "the southern land") for approximately 65,000 years, however population growth was relatively slow until the nineteenth century. Europeans had made some contact with Australia as early as 1606, however there was no significant attempt at settlement until the late eighteenth century. By 1800, the population of Australia was approximately 350,000 people, and the majority of these were Indigenous Australians. As colonization progressed the number of ethnic Europeans increased while the Australian Aboriginal population was decimated through conflict, smallpox and other diseases, with some communities being exterminated completely, such as Aboriginal Tasmanians. Mass migration from Britain and China After the loss of its American colonies in the 1780s, the British Empire looked to other parts of the globe to expand its sphere of influence. In Australia, the first colonies were established in Sydney, Tasmania and Western Australia. Many of these were penal colonies which became home to approximately 164,000 British and Irish convicts who were transported to Australia between 1788 and 1868. As the decades progressed, expansion into the interior intensified, and the entire country was claimed by Britain in 1826. Inland colonization led to further conflict between European settlers and indigenous Australians, which cost the lives of thousands of natives. Inward expansion also saw the discovery of many natural resources, and most notably led to the gold rushes of the 1850s, which attracted substantial numbers of Chinese migrants to Australia. This mass migration from non-European countries eventually led to some restrictive policies being introduced, culminating with the White Australia Policy of 1901, which cemented ethnic-European dominance in Australian politics and society. These policies were not retracted until the second half of the 1900s. Independent Australia Australia changed its status to a British dominion in 1901, and eventually became independent in 1931. Despite this, Australia has remained a part of the British Commonwealth, and Australian forces (ANZAC) fought with the British and their Allies in both World Wars, and were instrumental in campaigns such as Gallipoli in WWI, and the South West Pacific Theater in WWII. The aftermath of both wars had a significant impact on the Australian population, with approximately 90 thousand deaths in both world wars combined, as well as 15 thousand deaths as a result of the Spanish flu pandemic following WWI, although Australia experienced a significant baby boom following the Second World War. In the past fifty years, Australia has promoted immigration from all over the world, and now has one of the strongest economies and highest living standards in the world, with a population that has grown to over 25 million people in 2020.