The impacts associated with global climate change (e.g., sea-level rise, tropical storms, and warming temperatures) are expected to alter predator–prey interactions, foundation species, and plant community structure in coastal ecosystems. While the complex dynamics of these habitats have been examined under future climate predictions, few ecosystem models incorporate influences from fauna, such as the diamondback terrapin, the only estuarine turtle native to North America. This review examines the impacts of climate change on diamondback terrapins (Malaclemys terrapin) and the role that terrapins play as higher trophic level predators and keystone species in driving the dynamics of these ecosystems. We also review the potential implications of changes to terrapin populations on coastal ecosystems as a conservation challenge and suggest solutions to advance our understanding of those complex systems. Because of their role as a keystone and area-sensitive species that helps maintain healthy coastal habitats by foraging on herbivorous periwinkle snails, alterations to terrapin life history from climate change are expected, which could have significant impacts to the conservation of coastal habitats. Life history alterations could occur due to individual stressors, such as warming temperatures altering terrapin sex ratios. However, because of the complexity of these coastal systems, these stressors could also act additively or synergistically. Inclusion of faunal taxa such as the diamondback terrapin in modeling efforts examining climate change impacts to coastal ecosystems would better represent the complexity of these habitats thereby providing a more comprehensive evaluation of the entire ecosystem, resulting in more effective conservation strategies.