Australia and New Zealand have deep historical connections—geological, environmental, cultural, political, and economic—with Antarctica and the Southern Ocean. Yet while Australasia and the Southern Ocean are historically entangled, their historiographies are largely estranged. This article provides a survey of Australian and New Zealand histories of Antarctica, the subantarctic, and the Southern Ocean. I argue that historians in and of Australasia have contributed significantly to understandings of the region's southern hinterland, including the histories and legacies of Antarctic whaling, sealing, science, exploration, politics, and culture. These same connections and entanglements have rarely been used to shed light on Australian and New Zealand histories, but can offer new perspectives on Australasian histories of intercultural contact and exchange, mobilities, the frontier, imperialism, and internationalism. I argue that conceptualising Australia, New Zealand, and Antarctica as littorals of a ‘terraqueous’ Southern Ocean World provides a way to both generate new insights into this region's history and draw new connections with global, world, and oceanic histories.