This article undertakes a comparative analysis of settler colonial definitions of civilization in the expanding frontiers of the United States' "New South" and in southeastern Australia between the 1790s and the 1850s. The article notes that the United States is often omitted from comparisons of nineteenth-century settler societies, an omission that elides the social, cultural, and political similarities that the United States' republican form of settler civilization shared with settler colonial societies such as New South Wales in Australia. Specifically, the article assesses the important role that ideals of gender, sexual behavior, and racial formation had on evolving understandings of settler civilization in relation to the Cherokee in the United States and among Aboriginal tribes such as the Awabakal and Wiradjur in Australia. The evidence suggests that while white Americans and Australians shared a similar understanding of the gendered ideals required for the highest form of settler colonial civilization to develop on colonial frontiers, these ideals were malleable enough to help travel writers, settlers, and missionaries identify very different racial "problems" that need reforming if settler civilization was to flourish. Woven through this analysis are the responses of Cherokee Indians and Australian Aborigines to settler civilization—responses that reflect both the hegemony of settler colonial power and its contested nature in different settler colonial contexts.