Sharing global knowledge and practices while adapting them to local contexts is a central concern in innovation and sustainable development. In this paper, we examined how intermediary organisations promoting innovation can foster and enable the diffusion and local adaptation of knowledge, practices of open innovation and collaboration between universities, firms and social innovators. We studied three longitudinal, interlinked cases from Finland, Mexico and Nicaragua, moving from highly industrialised to emerging-economy contexts. We traced how innovation intermediaries support developing cultures of collaboration and the value co-creation by diffusing knowledge, getting actors together, sharing activities and supporting the engagement between organisations. Through observation, interviews, participatory action and self-reflection, we proposed a stepwise generic model for diffusion and adaptation. We argued that all steps and roles must co-exist to achieve successful transfers, and noted the evolutionary nature of the process and the importance of aligning the interests and activities of the actors. We contributed to sustainable development goals through the global diffusion of open innovation knowledge within the collaboration of universities, firms and social innovators. We noted the limitations of addressing three cases, while proposing directions for further research on the capabilities of actors, collaboration practices and the co-creation of value by actors.