Since the end of the Second World War, Australian nationalism has been widely conceptualised as self-contained, singular and uniform; as something that developed separately to Australia’s connection with Britain and empire. However, this focus on a distinctively Australian experience has produced an amnesia about the country’s British and imperial roots, and obscured local variations in the articulation of nationalism. By drawing on the work of historians who are re-examining Australia’s imperial past, this paper suggests nationalism was characterised in the colonies/states by a multilayered identity. Through a study of commemorative events in South Australia during the interwar years, it explores how the state’s imperial connection shaped and reflected its ideas of nationalism. It examines how South Australians viewed the empire and their place in it, and how their imperial identity worked with ideas of South Australian distinctiveness, and a developing continental identity. I argue that these commemorations necessarily celebrated SA’s community of interest: the protection and development of the Australian continent as part of the imperial project. In turn, this highlights the unfixed and contingent nature of nationalism. Rather than remaining static, Australian nationalisms were continuously reconfigured into communities of people that reflected particular aspects of their community of interest.