Climate change impacts island communities all over the world. Sea-level rise, an increase in the frequency and intensity of severe weather events, and changes in distribution and health of marine organisms are among the most significant processes affecting island communities worldwide. On islands of the Caribbean and southwestern Indian Ocean (SWIO), however, today’s climate change impacts are magnified by historical environmental injustice and colonial legacies, which have heightened the vulnerability of human and other biotic communities. For some islands, archaeological and paleoecological research offers an important record of precolonial climate change and its interplay with human lives and landscapes. The archaeological record suggests strategies and mechanisms that can inform discussions of resilience in the face of climate change. We detail climate-related challenges facing island Caribbean and SWIO communities using archaeological and paleoecological evidence for past climate change and human response and argue that these cannot be successfully addressed without an understanding of the processes that have, over time, disrupted livelihoods, reshaped land- and seascapes, threatened intergenerational ecological knowledge transfer, and led to increased inequality and climate vulnerability.