Co-production is one of the most important ideas in the theory and practice of knowledge and governance for global sustainability, including ecology and biodiversity conservation. A core challenge confronting the application of co-production has been confusion over differences in definition and practice across several disciplinary traditions, including sustainability science, public administration, and science and technology studies. In this paper, we review the theoretical foundations of these disciplinary traditions and how each has applied co-production. We suggest, at the theoretical level, the differences across disciplines are, in fact, more apparent than real. We identify several theoretical convergences that allow us to synthesize a strong conceptual foundation for those seeking to design and implement co-production work in programs of global sustainability research and policy.