The “One Health” approach is a comprehensive, integrated scientific framework that redefines health as a unified system grounded in the structural interconnections among human, animal, plant, and environmental health. It aims to achieve a sustainable balance and comprehensive improvements in health and environmental well-being, starting from the recognition that these components are not independent domains but rather interwoven systems that structurally depend on one another. This concept is grounded in a global institutional vision adopted by the international Quadripartite Partners composed of: (1) the Food and Agriculture Organization of the United Nations (FAO), represented by the International Plant Protection Convention (IPPC), in its role in protecting plant health; (2) the World Organisation for Animal Health (WOAH) in protecting animal health; (3) the World Health Organization (WHO) in protecting human health and preventing transboundary health risks; and (4) the United Nations Environment Programme (UNEP) in protecting ecosystems and ensuring the sustainability of natural resources. These partners work collectively to mainstream the One Health approach as a strategic tool for preventing global health threats, anticipating them, ensuring their early detection, coordinating responses, and promoting sustainable development. In this context, plant health is no longer a narrow technical agricultural field, but has become a structural component of the architecture of global health, as it represents a point of convergence between food and the environment. This article addresses a set of aspects that embody this structural interconnection and cannot be understood or managed except within a single, integrated perspective that makes plant health an active component of the global prevention system, rather than merely a productive sector within the agricultural economy.