Vulnerability is becoming an increasing concern in policy and legislation and as a focus for action in policing and criminal justice practice. Yet, concerns about the over-representation of vulnerable people in the criminal justice system are not new, with literature on the topic spanning more than five decades. What has come to the fore more recently, though, is a renewed conceptualisation and understanding of what vulnerability is when applied across disciplinary practices. Greater efforts at the operationalisation of vulnerability by practitioners in policing, justice and other areas of government have also expanded the reach of this organising concept.