Indian Australians or Indo-Australians are Australians of Indian ancestry. This includes both those who are Australian by birth, and those born in India or elsewhere in the Indian diaspora. Indian Australians are one of the largest groups within the Indian diaspora, with 783,958 persons declaring Indian ancestry at the 2021 census, representing 3.1% of the Australian population, and 673,352 stating that they were born India. If all Indian related ancestries are grouped together, then that number rises to 970,000, or 3.8% of the country's population. Furthermore, by June 2024, the Australia Bureau of Statistics reported that the Indian born population had increased 916,330 individuals, an increase of nearly 150,000.

Indians are the youngest average age (34 years) and the fastest growing community both in terms of absolute numbers and percentages in Australia.

In 2017–18 India was the largest source of new permanent annual migrants to Australia since 2016, and overall third largest source nation of cumulative total migrant population behind England and China, 20.5% or 33,310 out of 162,417 Australian permanent resident visas went to the Indians who also additionally had 70,000 students were studying in Australian universities and colleges, and Hindi (ranked 8th with 0.7% of total population) and Punjabi (ranked 10th with 0.6% of total population) are among the top 10 languages spoken in Australia. Among Indian origin religions, which also include non-Indians, are Buddhist (2.4% of total population or 563,700 people), Hindus (1.9% or 440,300) and Sikhs (0.5% or 125,900).

As of 2016, Indians were the highest educated migrant group in Australia with 54.6% of Indians in Australia having a bachelor's or higher degree, more than three times Australia's national average.

The long history of Indian migration to Australia has progressed "from 18th-century sepoys and lascars (soldiers and sailors) aboard visiting European ships, through 19th-century migrant labourers and the 20th century's hostile policies to the new generation of skilled professional migrants of the 21st century... India became the largest source of skilled migrants in the 21st century."

A study of Indigenous Australian DNA has found that Indigenous Australians may have mixed with people of Indian origin about 4,200 years ago. The same study showed that flint tools and Indian dogs may have been introduced from India at about this time. A 2012 paper reports that there is also evidence of a substantial genetic flow from India to northern Australia estimated at slightly over four thousand years ago, a time when changes in tool technology and food processing appear in the Australian archaeological record, suggesting that these may be related. One genetic study in 2012 by Irina Pugach and colleagues at the Max Planck Institute for Evolutionary Anthropology has suggested that about 4,000 years before the First Fleet landed in Australia (in 1788), some Indian explorers had settled in Australia and assimilated into the local population in roughly 2217 BC. The study by the Max Planck Institute for Evolutionary Anthropology found that there was a migration of genes from India to Australia around 2000 BC. The researchers had two theories for this: either some Indians had contact with people in Indonesia who eventually transferred those genes from India to Aboriginal Australians, or that a group of Indians migrated all the way from India to Australia and intermingled with the locals directly.

Most early explorations of Australia by various European colonial powers had an Indian connection. Indians had been employed for a long time on the European ships trading in Colonial India and the East Indies. Many of the early voyages to the Pacific either started or terminated in India and many of these ships were wrecked in the uncharted waters of the South Pacific. In 1606, the Dutch East India Company's ship, Duyfken, led by Willem Janszoon, made the first documented European landing in Australia. In 1627 the south coast of Australia was accidentally discovered by the Dutch East India Company explorer François Thijssen and named 't Land van Pieter Nuyts, in honour of the highest ranking passenger, Pieter Nuyts, extraordinary Councillor of India. In 1628 a squadron of Dutch East India Company ships was sent by the Governor-General of the Dutch East Indies Pieter de Carpentier to explore the northern coast. These ships made extensive examinations, particularly in the Gulf of Carpentaria, named in honour of de Carpentier.

Alexander Dalrymple (1737–1808), the Examiner of Sea Journals for the British East India Company, whilst translating some Spanish documents captured by Indian sepoys during the 1762 CE occupation of Philippines by the British India, found Portuguese navigator Luis Váez de Torres's testimony which led Dalrymple to discover and publish in 1770–1771 the existence of an unknown continent which he named as Terra Australis (or Southern Continent), this aroused widespread interest and prompted the British government in 1769 to order James Cook in HM Bark Endeavour to seek out the Southern Continent, which was discovered in June 1767 by Samuel Wallis in HMS Dolphin and named by him King George Island. The London press reported in June 1768 that two ships would be sent to the newly discovered island and from there to "attempt the Discovery of the Southern Continent". The British East India Trade Committee recommended in 1823 that a settlement be established on the coast of northern Australia to forestall the Dutch, and Captain J.J.G. Bremer, RN, was commissioned to form a settlement between Bathurst Island and the Cobourg Peninsula.