Au

Au, AU, au or a.u. may refer to:

Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands.

Austria ( (listen), ; German: Österreich [ˈøːstɐʁaɪ̯ç] (listen)), officially the Republic of Austria (German: Republik Österreich, listen ), is a land-locked country in Central Europe composed of nine federated states (Bundesländer), one of which is Vienna, Austria's capital and its largest city.

Augustus (Latin: Imperator Caesar Divi filius Augustus; 23 September 63 BC – 19 August AD 14) was a Roman statesman and military leader who became the first emperor of the Roman Empire, reigning from 27 BC until his death in AD 14. His status as the founder of the Roman Principate has consolidated an enduring legacy as one of the most effective and controversial leaders in human history.

Austin (UK: , US: ) is the capital city of the U.S. state of Texas and the seat of Travis County, with portions extending into Hays and Williamson counties.

Augustine of Hippo (; 13 November 354 – 28 August 430 AD) was a Roman African, early Christian theologian and Neoplatonic philosopher from Numidia whose writings influenced the development of the Western Church and Western philosophy, and indirectly all of Western Christianity.