The term ‘criminology’ will be used broadly, referring to the academic field as a whole, and hence including the study of the causes of crime, responses to crime including criminal justice, as well as to the field’s many sub-disciplines. The article begins by considering international and comparative criminology, before reviewing previous work that has raised the prospect of a ‘global criminology.’ The focus then shifts to consideration of the question, ‘what is criminology?’, prompted in particular by the various essays in Bosworth and Hoyle (eds) (2011). It is argued that this question usefully draws attention to certain problems currently facing Anglo-American criminology, and contends moreover that these issues are related in certain respects to issues that will face criminology as it globalises. Drawing from work by Wenger (1999) and others, a novel way of conceptualising the field of criminology is proposed, namely as a group of ‘communities of practice.’ The article shows how not only does this approach help model some of the challenges facing Anglo- American criminology both domestically and globally, but that it also suggests some practical measures that could be undertaken to help overcome these problems.