The two most well known Australian metahumans in the Marvel Universe are Gateway and Slipstream. Both characters are mass teleporters capable of moving themselves and an unspecified amount of mass great distances.
Gateway (mutant, teleportation; status: believed deceased)
The aboriginal mutant Gateway debuted when the Reavers forced him to teleport them during the "Mutant Massacre" storyline in 1986. He has made infrequent appearances in X-men stories since then. He was presumed killed by the Marauders for his knowledge of the Destiny Diaries in X-men Vol 2, #202. He is also the great-grand father of the X-man from the future named Bishop.
Gateway's power was the ability to generate trans-dimensional gateways: Gateway is in tune with the spiritual force of his people that allows him to create teleportational "gateways" from one location to another. Gateway creates these warp tunnels, which can traverse both time and space, by whirling his bullroarer over his head.
Gateway somehow causes a burning fire to appear before him when he creates one of his gateways, though the role that the fire and the bullroarer play in the creation and functioning of the gateways is unclear. The gateways can be used for both observation and transport. The exact limits of how much mass can be transported is yet to be revealed. There were no known limits to Gateway's teleportational range.
Slipstream (mutant, teleportation; status: depowered)
Davis Cameron, (Earth-616) from X-Treme X-Men, Vol: 1, #10
Wikipedia's entry on Slipstream:
Slipstream (Davis Cameron) and his sister Heather lived perfectly normal lives at Surfers Paradise in Australia. They did not know that their actual father was an underworld crime lord known as Viceroy, and upon his death they were attacked.
When Heather's life was endangered, Davis was informed by Sage that although he was never meant to be a mutant (his latent mutant gene was supposed to be passed down to his children) his mutant power might be helpful to her. He agreed to let her activate it, gaining a teleportational ability in the form of the "warp wave".
Later, when infiltrating the ship of the intergalactic warlord, Khan, Heather develops a more avian look, leading to speculation that the two have Shi'ar heritage. Ultimately, Davis is unable to see past his sister's alien appearance and leaves the X-Men.
Slipstream is confirmed to be among the mutants who lost their powers as a result of M-Day.
Jack Mead (mutant; telepathy, radar sense, status: unknown)
A lesser known individual working for the Weapon X program called Jack Mead, (codenamed Jack-in-the-Box) worked as a resident mind reader for the program. Jack was an Australian aboriginal whose mutant powers were telepathy and radar sense, which allowed him to scan his surrounding area. His powers had a side effect where his body became petrified and brittle every time he used them. He first appeared in Weapon X, Vol: 2, #5.