The guide to implementing the One Health Joint Plan of Action (OH JPA) at national level provides practical guidance on how countries can adopt and adapt the OH JPA to strengthen and support national One Health action. Building on the OH JPA theory of change, this guide describes three pathways and five key steps to implement the OH JPA at national level: Pathway 1 -- Governance, policy, legislation, financing and advocacy Pathway 2 -- Organizational and institutional development, implementation and sectoral integration Pathway 3 -- Data, evidence, information systems and knowledge exchange. The stepwise approach comprises: Situation analysis including stakeholder mapping and review of existing assessment results Set-up/strengthening of a multisectoral, One Health coordination mechanism Planning for implementation, including activity prioritization and leveraging of resources Implementation of national One Health action plans Review, sharing and incorporation of lessons learned.