Small island developing states (SIDS) are among the countries in the world that are most vulnerable to climate change and required to adapt to its impacts. Yet, there is little information in the academic literature about how SIDS are adapting to climate change, across multiple countries and geographic regions. This paper helps to fill this gap. Using a sample of 16 countries across the Atlantic, Indian Ocean and South China Sea, Caribbean and Pacific regions, this study has two main aims, to identify (1) national-level adaptation trends across climate, climate-induced and non-climate-induced vulnerabilities, sectors and actors, as reported in National Communications (NCs) to the United Nations Framework Convention on Climate Change (UNFCCC), and (2) typologies of national-level adaptation actions in SIDS. It identifies, codes and assesses 977 adaptation actions. These actions were reported as addressing 47 climate and climate-induced vulnerabilities and 50 non-climate-induced vulnerabilities and were undertaken in 37 sectors by 34 actors. The paper proposes five typologies of adaptation actions for SIDS, based on actions reported by SIDS. It specifically explores the implications of its findings for global adaptation strategies. As this work establishes a baseline of adaptation action in SIDS, it can assist national governments to gauge their adaptation progress, identify gaps in their adaptation effort and, thereafter, develop appropriate strategies for filling the gaps. It can also assist donors, whether bilateral or multilateral, to make more ‘climate-smart’ investment decisions by being able to identify the adaptation needs that are not being met in SIDS.