On November 10, 2021, the International Association of National Public Health Institutes (IANPHI) launched the IANPHI Roadmap for Action on Health and Climate Change at the United Nations Climate Change Conference (COP26) in Glasgow, in Scotland, during a side event titled "The Untapped Potential of National Public Health Institutes as Key Climate Actors." The roadmap highlights and advocates for the existing and potential key role of national public health institutes (NPHIs) in climate adaptation and mitigation, and how they contribute to climate policy, research, and action. Motivated by the urgent need to act in the interest of public health in light of the degradation of natural systems, IANPHI supports the development of NPHIs’ global capacity to serve as advocates and key actors in climate adaptation and climate change mitigation. The IANPHI roadmap is available in English, Arabic, French, Portuguese, and Spanish.