The One Health philosophy recognizes the inherent interconnectedness of human, animal, and environmental health and demands multidisciplinary collaboration to deliver resilient food systems and sustainable wellness. This chapter explores the synergy between the application of One Health principles and functional food manufacturing within the framework of how they reciprocally contribute toward disease prevention, stimulation of immunity, and addressing global health issues. The roots of One Health are traced back from ancient philosophy through its present application in the management of zoonoses, antimicrobial resistance, and food safety. Functional foods like probiotics, prebiotics, herbal additives, and omega-3 fatty acid fortified animal products are used as case studies to determine whether they can improve animal welfare, reduce dependency on antibiotics, and impart nutritional benefits in humans. The chapter thereafter elaborates on circular economy systems, animal welfare factors, and sustainable agriculture practices as key strategies in low-footprint safe, functional food production. Probiotics in animals, plant-based animal feeding systems, and omega-3 enriched diets define how dietary innovations create win–win situations for animals, humans, and the environment. Despite these accomplishments, challenges still linger in scientific integration, harmonization of regulation, and consumer acceptance. Future directions highlight the importance of personalized nutrition, biotechnology, and global collaboration for advancing One Health-based functional foods. Collectively, this chapter emphasizes that integrating One Health into functional food systems is not only a strategy to enhance public health but also a way toward sustainable agriculture, improved animal welfare, and conservation.