The health risks of a changing climate are immediate and multifaceted. Policies, plans, and programs to reduce climate-related health impacts exist, but multiple barriers hinder the uptake of these strategies, and information remains limited on the factors affecting implementation. Implementation science—a discipline focused on systematically examining the gap between knowledge and action—can address questions related to implementation and help the health sector scale up successful adaptation measures in response to climate change. Implementation science, in the context of a changing climate, can guide decision makers in introducing and prioritizing potential health adaptation and disaster risk management solutions, advancing sustainability initiatives, and evaluating and improving intervention strategies. In this article we highlight examples from Pacific Island countries and outline approaches based on implementation science to enhance the capacity of health systems to anticipate, prepare for, respond to, and recover from climate-related exposures.