Addressing climate change: Supplement to the WHO water, sanitation and hygiene strategy 2018–2025 accentuates the need for countries to integrate climate resilience into their WASH planning and policies, given the identification of climate change as a significant health threat. It highlights key focus areas including monitoring of climate-resilient WASH, integrating climate resilience into WASH risk management approaches such as water and sanitation safety planning, establishing climate-resilient WASH in health care facilities, expanding research on climate change’s impact on WASH-related health outcomes, strengthening environmental surveillance, controlling vector-borne diseases, and integrating WASH within climate change, health policy, and Integrated Water Resources Management (IWRM) frameworks. The supplement elaborates upon the WASH-related climate resilience work under the current WHO WASH strategy and will inform future strategies.