ABSTRACT Over the past 40 years, environmental justice activists and scholars have drawn greater attention to the disproportionate environmental burdens borne by marginalised communities. This includes the consequences of ‘nuclear colonialism’, a phenomenon defined as constituting ‘a system of domination through which governments and corporations target indigenous peoples and their lands to maintain the nuclear production process’. In this article, I seek to complicate this definition of nuclear colonialism by exploring the role of uranium mining in consolidating both British and Australian settler colonial power during the first half of the twentieth century. I will do so through an examination of Australian uranium’s roots and routes as both a manifestation and facilitator of settler colonialism in Australia between 1900 and 1955. Combining sources from both British and Australian archives, this article seeks to contribute to emergent scholarship on the colonial dimensions of mineral extraction in two ways. Firstly, by explicating the role uranium played in fuelling the extractive mentalities of settler colonial Australia. And secondly, by exploring uranium extraction’s contribution to the consolidation of the British Empire’s waning power in the mid-twentieth century.