Small island developing states are widely recognized as among the most vulnerable to the deleterious impacts of both the climate change and biodiversity loss crises. One nature-based solution, ecosystem-based adaptation (EBA), offers the ability to simultaneously address both these threats and to address several global Sustainable Development Goals, with primary benefits of EBA including water and food security, and coastal protection. This chapter examines the application of such measures in the Pacific Islands and their role in reducing the undesirable outcomes of these threats. It focuses on the application of EBA in four regionally widespread ecosystem types: coral reefs, mangroves, subsistence gardens, and rainforests and at a landscape level in water catchments. The chapter examines the ecosystem services each provides and examples of EBA measures that can sustain these services, particularly at the community (village) level. The most effective approaches build on the knowledge systems held by island communities. With the encouragement and facilitation of governments and other agencies, communities develop and implement locally relevant solutions by combining their traditional environmental knowledge with Western science. EBA measures in the Pacific may have significant adaptive benefits for food and water security and coastal and biodiversity protection. However, given that most EBA measures involve incremental change rather than transformation, their ability to meet the more severe challenges of long-term climate change may be limited.