Reduction of carbon emissions and climate-resilience in cities are becoming important objectives to be achieved in order to ensure sustainable urban development pathways. Traditionally, cities have treated climate mitigation and adaptation strategies in isolation, without addressing their potential synergies, conflicts or trade-offs. Recent studies have shown that this can lead to inefficiencies in urban planning, conflicting policy objectives and lost opportunities for synergistic actions. However, in the last few years, we have observed that cities are increasingly moving towards addressing both mitigation and adaptation in urban planning. Cities need to pay particular attention and understand the rationale of both policy objectives whilst considering the integration of the two policies in urban planning and decision-making. This study presents an analytical framework to evaluate the level of integration of climate mitigation and adaptation in cities’ local climate action plans. We tested this framework in nine selected major cities, representatives from all inhabited continents, which are frontrunners in climate action both in their regions and globally. We applied the framework in order to evaluate the level of mitigation and adaptation integration in cities’ CCAPs and further explored the different types of mitigation—adaptation interrelationships that have been considered. A scoring system was also devised in order to allow comparing and ranking of the different CCAPs for their level of integration of adaptation and mitigation. The paper draws good practices to support cities in developing climate change action plans in an integrated way.