A circular city is one that promotes a just transition from a linear to a circular economy across the urban space, through multiple city functions and departments and in collaboration with residents, businesses and the research community. In practice, this means shifting away from the linear economy’s “take, make, waste” model, and moving to an economic system where the value and utility of infrastructure, products, components, materials and nutrients is maintained for as long as possible. In a circular city, material loops are closed, meaning that existing materials are repeatedly cycled instead of becoming waste; resource extraction is also minimized. Through this transition, cities seek to improve resource access, lower emissions, protect and enhance biodiversity, and reduce social inequities. This Circular City Actions Framework can be used by local governments and city-based circular economy practitioners at any stage of their city’s circular economy transition to advance systemic approaches toward a more sustainable and circular economy.