Kalmar "Babban birnin Australiya" na iya komawa zuwa Babban Birnin Australiya (ACT), wanda yanki ne na tarayya na Ostiraliya wanda ke aiki a matsayin babban birnin kasar. Tana yankin kudu maso gabashin ƙasar kuma gida ne ga birnin Canberra, da kuma wasu ƙananan garuruwa da al'ummomi. An kafa Dokar ta ACT a cikin 1911 a matsayin wuri mai tsaka tsaki don wurin da sabon babban birnin tarayya yake, kuma a hukumance ya zama Babban Birnin Australiya a 1938.