The Australian Antarctic Territory is the part of Antarctica claimed by Australia. It consists of all the islands and territory south of 60 deg latitude and between 45 deg and 160 deg east longitude, except for Adelie Land.

The mainland territory was first claimed 24 August 1936, although Mawson Base, the first Australian station on the continent proper, was not established until 11 February 1954. However, since Australia's signature of the Antarctic Treaty, territorial claims are effectively suspended, and the Australian Antarctic Division administers the area, primarily by supporting various research projects.

Nevertheless, Australia issues postage stamps for the territory. The first issues came in 1957, and sporadically thereafter, settling into a pattern of an annual issue by the 1990s. All have been Antarctic-themed, and all are valid for postage in Australia, so in practice they are just Australian stamps with a different inscription.