This paper critically reviews ecosystem-based adaptation (EbA) approaches for food security under climate change, specifically for the Small Island Developing States (SIDS) comprising the Africa, Indian Ocean, Mediterranean and South China Sea (AIMS) region. The focus is on integrating different knowledge forms. An analysis of current EbA approaches for food security is undertaken, alongside a review of methodologies for integrating local and external knowledge. Key gaps and actions for EbA for food security in the AIMS region, and potentially further afield, are identified. The gaps indicate the lack of coherence in AIMS SIDS approaching food security, in terms of policies and actions not reflecting the ecosystem-food-climate nexus, the lack of a regional framework despite similarities amongst the SIDS, and the infrequency with which knowledge integration occurs. To fill these gaps, suggested actions highlight knowledge identification and combination, learning from others and from history, using local champions, and regularly monitoring and evaluating progress. These actions will push forward the EbA agenda through improved development and use of knowledge, better connections amongst the AIMS SIDS and farther afield, and more local-national-regional collaboration.