ABSTRACTSupervision is integral to social work practice; however, how it operates in day‐to‐day practice remains poorly understood. Existing research mainly comprises quantitative and qualitative accounts of social workers' and supervisors' experiences of supervision. More recently, a small number of studies examining the content of supervision have added to our understanding of what happens in supervision. However, supervisory interactions outside formal supervision have received scant empirical attention. This paper draws on an ethnographic study of four social work teams in England, exploring how formal and informal case discussion supports social workers' sensemaking. Data comprised observations of case talk in the office space (n = 21) and group case discussions (n = 2), recordings of one‐to‐one supervision (n = 17) and semi‐structured interviews (n = 22). Findings highlighted the importance of space in how social workers perceived and engaged with supervision. Supervisory spaces involve the interaction of physical, thinking and emotional spaces to create spaces that are supportive, task‐focused and reflective. Moreover, these supervisory spaces are not confined to formal one‐to‐one supervision or to the dyadic supervisor–supervisee relationship. This raises questions for how child protection social workers can be best supported, across diverse supervisory spaces and relationships, to ensure their practice is effective.