'Australasian' originates from the geographic name 'Australasia' combined with the adjectival suffix '-an'; 'Australasia' itself was formed from Latin 'australis' meaning 'southern' + 'Asia'.

'Australasia' was coined in the early 19th century from 'austral-' (from Latin 'australis', 'southern') + 'Asia'. The English adjective and noun 'Australasian' developed by adding the suffix '-an' to refer to things or people of that region.

Initially used mainly for geographic and biogeographic descriptions of the southern Asia-Pacific region, it has retained that sense and is also commonly used to describe people, organizations, and cultural items from that region.