Cities bear a transformative potential, as they currently represent large resource sinks in the linear system. Turning them into resource turntables could keep products and resources in use and recover resources from residues and waste flows at a large scale. The integration of circular economy principles into urban development planning presents an opportunity to create a systemic lever to reshape cities into more sustainable, resilient, and adaptable entities. Urban development plans can play an enabling role, providing the facilities and guiding principles needed to achieve this transformation. The task to implement circular economy in urban planning requires identifying the urban spatial and infrastructure requirements of diverse circular economy strategies, from reduce to recover. The chapter presents how the city of Vienna incorporated circular economy principles into its 10-year urban development plan (Stadtentwicklungsplan 2035), driven by the objective to use the potential of the circular economy to achieve its climate action targets. This provides an example of how circular economy enabling conditions can be mainstreamed into a city’s urban planning framework—a model that urban planners in other cities can adopt, and adapt to their objectives and local conditions. This chapter describes the step-by-step process applied in Vienna, from framing challenges to creating a typology of circular economy strategies and facilities, and deriving context-specific guiding principles for urban planning. Challenges and opportunities in implementing circular economy principles are discussed, emphasizing the importance of innovation, community engagement, resource efficiency, economic resilience, and collaborative partnerships in shaping the future of circular urban development.