Australasia is one of the world's great geographical regions. It is unified in natural history and geology because of its ancient origin as part of the supercontinent Gondwana. It is the geographical area which contains the Australasian ecozone.
Its islands are all south-east of the Bali–Lombok line, known as the Wallace Line, after Alfred Russel Wallace. The main political entities are Australia, Indonesia and New Zealand. The main islands are:
- New Caledonia
- New Guinea
- New Zealand