Planetary Health, a new trans-disciplinary field, calls for new efforts to simultaneously safeguard human health and the natural systems that underpin it. It encourages integrated approaches to address the health and the broader social, environmental and economic impacts of increasing pressures on our planet, and can be a useful frame for supporting implementation of the Sustainable Development Goals, ensuring that no one is left behind. This issue brief explores what is meant by planetary health, and how it can inform UNDP’s work at the nexus of environmental sustainability and climate change, disaster risk reduction, health, gender equality, and poverty alleviation. It offers examples of ongoing work and key entry points for future activities and partnerships.