Australia’s Indigenous population estimated at 2.2m before ‘demographic catastrophe’ of colonisation

A large crowd gathers and waves the Australian Aboriginal flag during an Invasion Day protest in Hyde Park in Sydney on 26 January 2026. Photograph: Dean Lewins/AAP

The number of Aboriginal and Torres Strait Islander people in Australia before colonisation was dramatically underestimated, according to new research that suggests many more of them were killed.

Modelling by a national research group puts the population levels before the 1788 first fleet arrived at 2.2 million, compared with early estimates of 250,000 people.