Programs and projects are important vehicles for exploring and implementing circular developments at different levels and across them. Organizations engage in various efforts to embed circularity into their operations as well as collaborate in inter-organizational programs and projects to achieve broader ecosystem-level circularity effects. Better understanding of circularity in and through projects and programs has the potential to yield new insights that are theoretically and actionably meaningful. Interesting areas of investigation include, for example: how new projects are integrated into existing circular frameworks at the firm and system levels; how circularity at the project level can be used for piloting and demonstration to support circular scale-up; and how global or universal standards for circularity are interpreted uniquely or otherwise at the project scale. The special issue attempts to make progress in building a comprehensive framework and knowledge base for advancing circularity and circular economy solutions in project management, through a holistic perspective that includes dynamics both within organizations and the broader operating environment. We draw attention to both the strategic and operational aspects of circularity and encourage authors to consider ways in which circularity is implemented in ecosystems, companies’ supply chains, manufacturing operations, and managerial sensemaking, mindsets, and decision making at all levels of projects and programs.