Little progress has been made in recent years toward achieving a fully circular economy by 2050. Implementing circular urban supply chains is a major economic transformation that can only work if significant coordination problems between the actors involved are solved. On the one hand, this requires the implementation of efficient urban collection technologies, where process industries collaborate hand-in-hand with manufacturers, urban waste treatment, and city logistics specialists and are supported by digital solutions for visibility and planning. But on the other hand, it also requires implementing regional and urban ecosystems connected by innovative CO2-neutral circular city logistics systems smoothly and sustainably managing the regional flow of resources and data, often at large and with interfaces between industrial processes and private and private and public actors. What are relevant research questions from a city logistics perspective?