Blue foods – fish, invertebrates, algae and aquatic plants captured or cultured in freshwater and marine ecosystems – play a central role in food and nutrition security for billions of people and are a cornerstone of the livelihoods, economies, and cultures of many coastal and riparian communities. Blue food systems are extraordinarily diverse, involving thousands of species in many different production systems and supporting a wide array of cultures and diets. Many blue foods are rich in please see back-page) bioavailable micronutrients and can be produced in ways that are more environmentally sustainable than terrestrial animal-source foods. Yet despite their unique value and interconnections with terrestrial food systems, blue foods are often left out of food system analyses, discussions, decisions, and solutions. Realizing the potential of blue foods to play a central role in ending malnutrition and in building healthy, nature-positive and resilient food systems will require that governments embed blue foods in food- system governance. Here, we focus on three central imperatives for policymakers.