Can you name every country with at least one airport with direct flights to/from any Australian airport?
There are 14 international airports in Australia: Adelaide, Brisbane, Cairns, Canberra, Christmas Island, Darwin, Gold Coast, Hobart, Melbourne, Newcastle, Norfolk Island, Perth, Sunshine Coast and Sydney. The upcoming Western Sydney Airport will also be an international airport.
Most dependencies (e.g Cook Islands, Hong Kong, etc) don't count (but there's a French territory that does)
Antarctica is not a country, it is a continent, so it also doesn't count