The dollar is the currency of the Commonwealth of Australia, including Christmas Island, Cocos (Keeling) Islands, and Norfolk Island, as well as the independent Pacific Island states of Kiribati, Nauru and Tuvalu. The Australian dollar's ISO 4217 code is AUD but it is often abbreviated with the dollar sign $. A$ or AU$ is often used informally to distinguish it from other dollar-denominated currencies. It is subdivided into 100 cents.

The Australian dollar is currently the sixth-most-traded currency in world foreign exchange markets (behind the euro,U.S. dollar, the yen, the pound sterling, and the swiss franc), accounting for approximately 4–5% of worldwide foreign exchange transactions. The Australian dollar is popular with currency traders due to relatively high interest rates in Australia, the relative lack of government intervention in the foreign exchange market, the general stability of the economy and the government, as well as the prevailing view that it offers diversification benefits in a portfolio containing the major world currencies (especially because of its greater exposure to Asian economies and the commodities cycle).