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.

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.

Chart and table of population level and growth rate for the Melbourne, Australia metro area from 1950 to 2025. United Nations population projections are also included through the year 2035.

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.

The earliest point where scientists can make reasonable estimates for the population of global regions is around 10,000 years before the Common Era (or 12,000 years ago). Estimates suggest that Asia has consistently been the most populated continent, and the least populated continent has generally been Oceania (although it was more heavily populated than areas such as North America in very early years). Population growth was very slow, but an increase can be observed between most of the given time periods. There were, however, dips in population due to pandemics, the most notable of these being the impact of plague in Eurasia in the 14th century, and the impact of European contact with the indigenous populations of the Americas after 1492, where it took almost four centuries for the population of Latin America to return to its pre-1500 level. The world's population first reached one billion people in 1803, which also coincided with a spike in population growth, due to the onset of the demographic transition. This wave of growth first spread across the most industrially developed countries in the 19th century, and the correlation between demographic development and industrial or economic maturity continued until today, with Africa being the final major region to begin its transition in the late-1900s.

While the European colonization and settlement of other world regions largely began in the 16th and 17th centuries, it was not until the 19th century when the largest waves of migration began to take place. In early years, migration rates were comparatively low; in all of the Americas, the slave population actually outnumbered that of Europeans for most of the given period. Then, with the development of steam ships, intercontinental travel became more affordable and accessible to the masses, and voluntary migration from Europe rose significantly. Additionally, larger numbers of Asian migrants, especially from India and China, migrated to Australia, the Caribbean, and U.S. from the mid-1800s; although the U.S. and Australia both introduced policies that limited or prevented Asian immigration throughout most of the early 1900s. International migration between 1913 and 1950 was also comparatively low due to the tumultuous nature of the period, which involved both World Wars and the Great Depression.

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.

In 1820, the islands of present-day New Zealand had a population of approximately 100,000 people. This figure would fall until the early 1840s, partly as a result of European diseases brought by colonizers, and a series of destructive inter-tribal wars among the Māori peoples. These conflicts were named the Musket Wars due to the European weapons whose introduction instigated the conflicts, and the wars saw the deaths of between 20,000 and 40,000 Māori, from 1807 to 1837. After falling to just 82 thousand in the 1840s, the population would begin to rise again in 1841 following the establishment of New Zealand as an official British colony, with a strong promotion of European settlement by British citizens sponsored by the Church of England. European migration to New Zealand was low in these early decades, but increased in the mid-19th century, particularly following the discovery of gold in New Zealand’s South Island in the 1860s. This growth would continue throughout the 1870s, in part the result of a strong promotion of mass migration from Britain by Premier Julius Vogel’s administration.

Early 20th century However, between 1881 and the 1920s, the New Zealand government heavily restricted Asiatic migration to the islands, resulting in a fall of population growth rate, which would remain until the Second World War. The country would experience a dip in population during the First World War, in which New Zealand would suffer approximately 18,000 military fatalities, and another 9,000 lost to the coinciding Spanish Flu epidemic. The population would stagnate again in the Second World War, which resulted in the death of almost 12,000 New Zealanders. In the years following the war, New Zealand would see a significant increase in population due to the mixture of a baby boom and a migrant spike from Europe and Asia, following a large demand for unskilled labor. Recent decades This increase continued for several decades, until international factors, such as the oil crises of 1973 and 1979, and the UK's accession to the European Economic Communities (which ended most of New Zealand's trade agreements with Britain; it's largest trade partner), greatly weakened New Zealand's economy in the 1970s. As a result, population growth stagnated during the 1970s, while economic problems persisted into the early 2000s. In contrast, the Great Recession of 2008 did not impact New Zealand as severely as most other developed nations, which allowed the economy to emerge as one of the fastest growing in the world, also leading to dropped unemployment levels and increased living standards. In 2020, with a population of almost five million people, New Zealand is regarded as one of the top countries in the world in terms of human development, quality of life and social freedoms.

Cette statistique présente l'évolution de la population mondiale de 1950 à 2024, ainsi que les prévisions de l'ONU jusqu'à 2100. La population mondiale s'élevait à environ 8,16 milliards de personnes en 2024. Comme présenté ci-dessus, le nombre total de personnes dans le monde a au moins doublé depuis les années 1950, et cette augmentation se poursuit. Un coup d’œil à l'évolution de la population mondiale depuis le début de l'ère commune permet de constater que cette augmentation est sans précédent. La première hausse importante de la population a eu lieu au 14ème siècle, après les périodes de peste qui entrainèrent la mort d'environ 25 millions de personnes dans le monde. Par la suite, la population mondiale a lentement mais régulièrement progressé pour finalement atteindre les valeurs records recensées entre 1950 et 2000. La majorité de la population mondiale vit sur le continent asiatique, comme le montre la statistique sur la population mondiale par continent. Dans environ cent ans, on estime que la population du continent africain devrait atteindre des niveaux similaires à ceux de l'Asie aujourd'hui. En prévision du développement de la population mondiale, on estime que les chiffres devraient atteindre les 10 milliards d'habitants au 22ème siècle. L'augmentation de la population présente un risque grandissant pour la planète, puisque cette montée en flèche correspond à une augmentation équivalente de consommation en nourriture et en ressources. Les scientifiques s'interrogent quant à raréfaction des ressources naturelles comme le pétrole et la nourriture, qui met en danger le genre humain et l'écosystème mondial. De nos jours, le nombre de personnes sous-alimentées/en situation de famine dans le monde est légèrement à la baisse, mais les prévisions annoncent un avenir plus sombre.