The South Sandwich Islands are a volcanic archipelago in the Southern Ocean that are remote and largely pristine, but experience high levels of natural disturbance, and pose interesting and challenging questions for conservation and management. The archipelago lies to the south of the oceanic Antarctic Polar Front, in the biological transition region between the sub-Antarctic and maritime Antarctic. They host the southern boundary for some sub-Antarctic communities and the northern boundary for some from the maritime Antarctic. Vertebrate communities are dominated by Chinstrap and Macaroni penguins in the north and Adélie penguins in the south. Terrestrial plant and animal communities are not so well differentiated. Instead, their composition and extent are more influenced by the distribution of geothermally-warmed ground, although the archipelago again hosts representatives of both sub- and maritime Antarctic origin. We review the current knowledge about the islands’ biodiversity, the influence of contemporary change on the archipelago, and their regional importance to Southern Ocean species. We summarise likely threats to the archipelago’s biodiversity, and pose questions that are important for developing effective management strategies particularly in the contexts of climate change, fishery exploitation and human visitation. We anticipate that, while climate change and fisheries will likely lead to a range of impacts on the islands’ biota, introduced species are likely to be the most immediate and largest threat to ecosystems on land in the archipelago. Given the ephemeral nature of populations across all trophic levels, we suggest that the islands be managed as one unit rather than individually, and we recommend practical changes to risk assessment, permitting and to consider increasing the no take area in the existing Marine Protected Area to protect penguin foraging areas.