Abstract Learning, and how we learn, is integral for the governance of complex social‐ecological systems. With the growing interest in knowledge co‐production comes a need to further study how to better enable learning between different actors engaged in dialogue‐based processes. We use an empirical case of a workshop series centred on collaborative water and landscape governance on Öland, Sweden, to explore how a process partly designed for relating to others supported participating actors in their learning. Based on an analysis of reflection exercises and semi‐structured interviews conducted with all 17 actors, we assessed learning outcomes using competencies in sustainability as the analytical lens. Competencies in sustainability allowed us to investigate how and why actors developed individual changes in perception and built and strengthened the skills and attitudes needed to deal with complex challenges in practice. We provide empirical evidence that relational learning takes place in knowledge co‐production processes and supports actors in competency development. The detailed accounts of changed understandings of the problem, pathways forward and especially other actors show that relational learning plays a key role in addressing misunderstandings and conflicts of interest, which could make collaborative governance arrangements more feasible. We found that a mix of discussion and interaction formats and activities specifically designed for relational learning create opportunities for engaging with plural understandings, perspectives, interests, norms and values. Hereby, actors need to draw on active listening, compassionate communication, collaborative and critical self‐reflection skills as well as positive attitudes towards plurality. Different assessment approaches embedded in a process provide time for reflection and revisiting the learning. We argue that designing for, supporting and tracing relational learning in knowledge co‐production leverages dialogue‐based processes as a suitable tool for nurturing collective action for addressing sustainability challenges in complex social‐ecological systems. Read the free Plain Language Summary for this article on the Journal blog.