Aboriginal Australians are the various indigenous peoples of the Australian mainland and many of its islands, excluding the ethnically distinct people of the Torres Strait Islands.

Humans first migrated to Australia 50,000 to 65,000 years ago, and over time formed as many as 500 linguistic and territorial groups. In the past, Aboriginal people lived over large sections of the continental shelf. They were isolated on many of the smaller offshore islands and Tasmania when the land was inundated at the start of the Holocene inter-glacial period, about 11,700 years ago. Despite this, Aboriginal people maintained extensive networks within the continent and certain groups maintained relationships with Torres Strait Islanders and the Makassar people of modern-day Indonesia.

Over the millennia, Aboriginal people developed complex trade networks, inter-cultural relationships, law and religions, which make up some of the oldest continuous cultures in the world. At the time of European colonisation of Australia, the Aboriginal people spoke more than 250 different languages, possessed varying degrees of technology, and lived in various types of settlements. Languages (or dialects) and language-associated groups of people are connected with stretches of territory known as "Country", with which they have a profound spiritual connection.

Contemporary Aboriginal beliefs are shaped by traditional beliefs, the disruption of colonisation, religions brought to the continent by later migrants, and contemporary issues. 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. Traditional cultural beliefs are passed down and shared through dancing, stories, songlines, and art that collectively weave an ontology of modern daily life and ancient creation known as the Dreaming.

Studies of Aboriginal groups' genetic makeup are ongoing, but evidence suggests that they have genetic inheritance from ancient Asian peoples. Aboriginal Australians and Papuans shared the same paleocontinent Sahul, but became genetically distinct about 37,000 years ago. Aboriginal Australians have a broadly shared, complex genetic history, but only in the last 200 years have they been defined by others as, and started to self-identify as, a single group. Aboriginal identity has changed over time and place, with family lineage, self-identification, and community acceptance all of varying importance.

The 2021 census shows that there were over 944,000 Aboriginal people, comprising 3.7% of Australia's population. Over 80% of Aboriginal people today speak English at home, and about 77,000 speak an Indigenous language at home. Aboriginal people, along with Torres Strait Islander people, suffer a number of severe health and economic deprivations in comparison with the wider Australian community.

Archeological evidence indicates that the ancestors of today's Aboriginal Australians first migrated to the continent 50,000 to 65,000 years ago. Genomic studies suggest that the peopling of Australia happened between 43,000 and 60,000 years ago.

Early human migration to Australia was achieved when it formed a part of the Sahul continent, connected to the island of New Guinea via a land bridge. This would have nevertheless required crossing the sea at the Wallace Line. It is also possible that people came by island-hopping via an island chain between Sulawesi and New Guinea, reaching North Western Australia via Timor. As sea levels rose, the people on the Australian mainland and nearby islands became increasingly isolated, some on Tasmania and some of the smaller offshore islands when the land was inundated at the start of the Holocene, the inter-glacial period that started about 11,700 years ago.