Indigenous Australians are the various Aboriginal Australian peoples of Australia, and the ethnically distinct people of the Torres Strait Islands. The terms Aboriginal and Torres Strait Islander peoples, First Nations of Australia, First Peoples of Australia and First Australians are also common. Many Indigenous Australians prefer to identify with their specific cultural group.

Estimates from the 2021 census show there were 983,700 Indigenous Australians, representing 3.8% of the Australian populations. Of these Indigenous Australians, 92% identified as Aboriginal, 4% identified as Torres Strait Islander, and 4% identified with both groups. About 84% spoke English at home and 9% spoke an Australian Indigenous language at home. Just over half hold secular or other spiritual beliefs or no religious affiliation; about 40% are Christian; and about 1% adhere to a traditional Aboriginal religion.

The ancestors of Aboriginal Australians moved into what is now the Australian continent about 50,000 to 65,000 years ago, during the last glacial period, arriving by land bridges and short sea crossings from what is now Southeast Asia. The ancestors of today's Torres Strait Islanders arrived from what is now Papua New Guinea around 2,500 years ago, and settled the islands on the northern tip of the Australian landmass.

Aboriginal Australians were complex hunter-gatherers with diverse economies and societies. There were about 600 tribes or nations and 250 languages with various dialects. Certain groups engaged in fire-stick farming and fish farming, and built semi-permanent shelters. The extent to which some groups engaged in agriculture is controversial. Torres Strait Islanders were seafarers and obtained their livelihood from seasonal horticulture and the resources of their reefs and seas. They also developed agriculture on some of their islands. Villages had appeared in their areas by the 14th century.

The Indigenous population prior to British settlement in 1788 has been estimated from 318,000 to more than 3,000,000. A population collapse, principally from new infectious diseases, followed British colonisation in 1788. Massacres, frontier armed conflicts and competition over resources with British settlers also contributed to the decline of the Aboriginal population.

From the 1930s, the Indigenous population began to recover and Indigenous communities founded organisations to advocate for their rights. From the 1960s, Indigenous people won the right to vote in federal and state elections, and some won the return of parts of their traditional lands. In 1992, the High Court of Australia, in the Mabo Case, found that Indigenous native title rights existed in common law. By 2021, Indigenous Australians had exclusive or shared title to about 54% of the Australian land mass. Since 1995, the Australian Aboriginal flag and the Torres Strait Islander flag have been official flags of Australia.

From the 19th to the mid-20th century, government policy removed many mixed heritage children from Aboriginal communities, with the intent to assimilate them to what had become the majority white culture. In 1997 the Australian Human Rights Commission found that the policy constituted genocide.

There are a number of contemporary appropriate terms to use when referring to Indigenous peoples of Australia. In contrast to when settlers referred to them by various terms, in the 21st century there is consensus that it is important to respect the "preferences of individuals, families, or communities, and allow them to define what they are most comfortable with" when referring to Aboriginal and Torres Strait Islander people.