Abstract: Heterosexualism is inextricably tied to coloniality and modernity. This paper explores the potential of Argentinian philosopher Maria Lugones’ theorisations of heterosexualism and the colonial/modern gender system for sustained critical engagement with settler colonialism in so-called Australia. ‘Heterosexualism’ refers to a system of relations between settlers and Indigenous peoples characterized by racialized and gendered power dynamics. Lugones’ theory on the colonial/modern gender system unpacks the utility of social and intellectual investment in universalised categories including race, gender and sexuality. Such categories are purported to be biological, thus, prior to culture, settlers and colonial institutions. However, the culturally specific nature of knowledge produced about race, gender and sexuality reveals that the origins, and indeed the prevalence, of heterosexualism in Australia is inextricable from settler colonialism. This paper exhibits how heterosexualism and the colonial/modern gender system operate in service of settler colonialism, facilitating settler dominance and reproduction on Aboriginal and Torres Strait Islander lands.