The size and composition of the Australian population has shifted since the dismantling of the discriminatory White Australia Policy during the 1970s, yet its immigration system and border control remain highly regulated. Despite this, detailed information about the specific locations that immigrants arrive to or depart from within Australia are not available. The picture is further compounded by inconsistencies in the measurement of flows and geographic boundaries over time. To address these issues, we obtained available immigration and emigration flow data provided by the Australian Bureau of Statistics at the state and territory level, and developed methods to harmonise the available data, estimate missing elements and disaggregate to a sub-state geography. The methods are applied to 19 birthplace-specific populations across 47 areas in Australia for annual time periods from 1981 to 2016. This research addresses the need for more detailed estimates of demographic events so that a better understanding of the mechanisms and differences underlying regional population change may be provided.