INTRODUCTION: Self-regulated learning (SRL) in medical education is important for successful learning and safe patient care. However, supervisors may be unaware of behaviours that explicitly facilitate or inhibit their students' or residents' SRL, therefore this BEME review explores the role of the supervisor in SRL in clinical environments. METHODS: A qualitative systematic review using meta-aggregation was performed, seeking to draw on the knowledge of included studies and the participants those studies represent to create context-rich recommendations that are relevant and applicable to practice. Categories were developed from individual findings and then synthesised in the form of guidance. RESULTS: Twenty-two studies were included. Six categories were developed. A supervisor who facilitates SRL is: adaptive, engaged and supportive, builds trusting relationships, is knowledgeable, learner-centred, and crafts the architecture of the clinical learning environment. CONCLUSIONS: Within the categories, reciprocal trust and dialogue creates a positive cycle of supervisor-learner engagement which facilitates SRL, but due to the power imbalance inherent in the supervisor-learner relationship, the supervisor needs to make the first move. The curriculum has an important role to play in fostering supervisor-learner relationships. Supervisor beliefs about their role, and the architecture of the clinical learning environment can facilitate or inhibit SRL.