Australia

[DaisyDoo]

who discovered Australia

[Clanad]

Not known for sure... the best candidate for modern discovery (the Aborigines have been there for anywhere between 25,000 to 110,000 years ago) are the Portuguese... A series of maps dating from the sixteenth century, called the Dieppe maps, may or may not show the east coast of Australia. If they do, a Portuguese expedition must have visited the north and east coasts of Australia more than two hundred years before James Cook's voyage in 1770...

[Quizmonster]

The Aborigines obviously discovered it first, thousands of years ago, as C says above.. For something a little more certain than the potentiality of the Dieppe maps and if you are referring to European 'discovery' in the 17th/18th centuries, there are various claims.
Dirk Hartog, a Dutch explorer, landed in Shark Bay in Western Australia in 1616. In 1642, Abel Tasman, another Dutchman, discovered the island of Tasmania - now part of Australia. William Dampier was the first Englishman to set foot there when he landed on the west coast in 1689. Captain James Cook's expedition did not get there until 1770, a century and a half after the first Europeans landed. For some reason, everyone seems to think he discovered the place! He was only the first to land on the east coast, to make any serious claim to the territory and to begin settlement of it.

[heathfield]

Gordon McIntyre, in his book 'The Secret Discovery of Australia', puts forward much evidence for the Portuguese being the first. They had a settlement in Timor by 1516. Timor fishermen seasonally fished the waters on the northern coast of Australia, and the Portuguese must have learned about it from them.
Have a look here, (but note the compass rose on the map - South is at the top!)

[Clanad]

I can always depend on Q to enrich my vocabulary... excellent word that... potentiality!... I've placed it in my Word of the Day file... thanks!

[Quizmonster]

Seeing your response here, C, I felt I had to do a quick dictionary check in case I had just invented the word! Turns out it does exist, I'm happy to say, and has been in use since the 17th century.

[jno]

discounting the aborigines (as every white Australian does), probably the Dutch. They initially made their way to the Spice Islands (Indonesia etc) by following the coast of Africa down, up the other side and then across south of India. But this meant a lot of unpleasant time spent in the tropics and the monsoon belt, and they figured it would be easier just to sail due east from the southern tip of Africa and then turn north. In all probability they bumped into western Australia while trying this out. Hartog's one possibility, as Quizmonster mentions. As I recall, there's a lot about this in the museum in Perth or Fremantle, if you're down that way at all.

[heathfield]

Cornelis de Jode's atlas 'Speculum Orbis Terrae' published in Holland in 1593 shows an animal on the title page that is more likely to be a kangaroo than any other animal. It's caused a lot of controversy over a lot of years. See here.
Historians always seem to do their utmost to deny anything that runs against (their) current opinion. Europeans in the Americas 20,000 years ago? There's an example! They turn apoplectic at the very thought.
I'd much rather they said, ' That sounds interesting. Let's research the possibility'.