Mandaean Australians are Australians of Mandaean descent or Mandaeans who have Australian citizenship. Most Mandaeans in Australia live in Greater Western Sydney.

As of 2023, Australia has the largest Mandaean population in the world, followed by Sweden (which has the largest Mandaean population in Europe) and the United States.

The Sydney metropolitan area in Australia has the largest Mandaean diaspora community in the world. The community is centered in Greater Western Sydney suburbs such as Fairfield, Liverpool, and Penrith. In Liverpool, the main mandi (Beth Manda) is Ganzibra Dakhil Mandi. The Sabian Mandaean Association of Australia has purchased land by the banks of the Nepean River at Wallacia, New South Wales, where Wallacia Mandi is currently being built. Another mandi in Greater Sydney is Yahya Yuhana Mandi (or Mandi Yehya Youhanna), located in Prestons.

In Western Sydney, Mandaeans mainly perform masbuta (baptisms) at Lighthorse Park in Liverpool, Yahya Yuhana Mandi, and Wallacia Mandi.

The Sabian Mandaean Association in Australia is the largest Mandaean association in Australia. Religious affairs are managed by the Mandaean Synod of Australia.