There is evidence that poor sleep mitigates recovery from substance dependence and increases risk of relapse. However, to date research literature is located within biomedical, clinical and psychological paradigms. To complement the extant work, this article offers a sociological exploration of sleep in the context of recovery from dependence on alcohol and/or other drugs. Drawing on qualitative data generated through interviews with 28 men and women living in residential rehabilitation settings in England, we provide a detailed exploration of sleep practices focusing on how these are enacted throughout the night. We offer the concept of ‘sleepfulness’ to suggest that sleep should not be understood simply as being other than awake; rather it involves a myriad of associations between diverse actants – human and non‐human – that come to ‘fill up’, enable and assemble sleep. Together these empirical insights and conceptualisations disturb the ontology of sleep and point to the fulsome dimensions of the category.