The manufacturing industry faces the challenge of using resources more efficiently and implementing circular practices. A promising pathway is to establish a circular economy (CE) through additive manufacturing (AM), enabling on-demand production with low material input and allowing the use of recycled materials. Despite this potential, practical barriers hinder its adoption and are insufficiently understood from a multi-stakeholder perspective. This paper combines stakeholder theory with the circular supply chain management concept in a qualitative multiple-case study to examine the perspectives and interactions of the actors involved. The findings separate the general technical adoption barriers of AM from the socioeconomic and relational barriers of circularity, which arise from power asymmetries, information asymmetries, and coordination failures among interdependent actors of differing salience. These barriers vary substantially with firms’ initial conditions, including their AM technology maturity, their engagement in closed-loop practices, and the managerial relevance they assign to circularity. The study develops five propositions based on the cross-case analysis and identifies three distinct pathways from barrier to solution for firms at different stages of circular supply chain development. Trust-based partnerships between manufacturing and recycling companies can close material loops locally, but they remain fragile amid price competition from virgin materials. Durable circularity therefore requires governance safeguards, including guaranteed-offtake contracts, verifiable production information, and consolidated reverse logistics, all supported by regulatory intervention. The study contributes to the CE and operations management literature by providing a deeper understanding of these barriers and proposing actionable measures for stakeholders to promote circularity in the specific AM domain.