This work examines existing inter-organizational configurations with the goal to identify and evaluate the key elements boosting Circular Bioeconomy (CBE) in the bio-based plastics industry. Indeed, while it is clear that multi-stakeholder engagement, together with cooperation, coordination and collaboration mechanisms, play a pivotal role in accelerating value creation and preservation for bio-based plastics, there is still the need to understand how these dynamics affect product development processes, end-user experiences and ultimately, the full circularity of the solutions proposed. Based on a conceptual framework, this study provides a structured lens to scrutinize the varying degrees of engagement and synergy among diverse entities operating in the bio-based plastics industry. Specifically, Alliances, Associations, Collaborative Research and Development, Consortia, Joint Ventures, Networks and Strategic Partnerships have been investigated. For each engagement mode, we delineate the scope, type and number of stakeholders involved, their specific roles, the motives addressed and funding involved, the operational timeframe, and the degree of innovation that resulted. Furthermore, the framework addresses factors that critically influence the strength of cooperation, coordination and collaboration mechanisms, such as trust, information, resources, and power. Drawing on real-world cases, we then present a non-exhaustive list of inter-organizational configurations already in place in the field of CBE. The work aims to help researchers, practitioners, and decision-makers to dissect and interpret the nature of inter-organizational dynamics among multiple stakeholders, in order to facilitate the understanding of the elements that drive successful synergies across organizational boundaries and boost a more effective CBE in the overall bio-based plastics industry.