The languages of Australia are the major historic and current languages used in Australia and its offshore islands. Over 250 Australian Aboriginal languages are thought to have existed at the time of first European contact. English is the majority language of Australia today. Although English has no official legal status, it is the de facto official and national language. Australian English is a major variety of the language with a distinctive accent and lexicon, and differs slightly from other varieties of English in grammar and spelling.

Around 120 to 170 Indigenous languages and dialects are spoken today, but many of these are endangered. Creole languages such as Kriol and Yumplatok (Torres Strait Creole) are the most widely-spoken Indigenous languages. Other distinctively Australian languages include the Australian sign language Auslan, Indigenous sign languages, and Norf'k-Pitcairn, spoken mostly on Norfolk Island.

Major waves of immigration following the Second World War and in the 21st century considerably increased the number of community languages spoken in Australia. In 2021, 5.8 million people used a language other than English at home. The most common of these languages were Mandarin, Arabic, Vietnamese, Cantonese, Punjabi, Greek, Italian and Hindi.

English was introduced into Australia on British settlement in 1788 and in the following decades gradually overtook Indigenous languages to become the majority language of Australia. Although English is not the official language of Australia in law, it is the de facto official and national language. It is the most widely spoken language in the country, and is used as the only language in the home by 72% of the population. The increase in the migrant population over the past decade has seen a decline in the number of people speaking only English at home.

Australian English is a major variety of the language with a distinctive accent and lexicon, and differs slightly from other varieties of English in grammar and spelling. General Australian serves as the standard dialect.

Humans arrived in Australia 50,000 to 65,000 years ago but it is possible that the ancestor language of existing Indigenous languages is as recent as 12,000 years old. Over 250 Australian Aboriginal languages are thought to have existed at the time of first European contact. The National Indigenous Languages Survey (NILS) for 2018-19 found that more than 120 Indigenous language varieties were in use or being revived, although 70 of those in use are endangered. The 2021 census found that 167 Indigenous languages were spoken at home by 76,978 Indigenous Australians. NILS and the Australian Bureau of Statistics use different classifications for Indigenous Australian languages.

According to the 2021 census, the classifiable Aboriginal and Torres Strait Island languages with the most speakers are Yumplatok (Torres Strait Creole) (7,596 speakers), Kriol (7,403), Djambarrpuyngu (3,839), Pitjantjatjara (3,399), Warlpiri (2,592), Murrinh Patha (2,063) and Tiwi (2,053). There were also over 10,000 people who spoke an Indigenous language which could not be further defined or classified.

Three languages are spoken on the islands of the Torres Strait, within Australian territory, by the Melanesian inhabitants of the area: Yumplatok (Torres Strait Creole) (7,596 speakers used the language at home in 2021), Kalaw Lagaw Ya (875 speakers) and Meriam Mir (256 speakers). Meriam Mir is a Papuan language, while Kalaw Lagaw Ya is an Australian language.