Community Operational Research (Community OR) has been an explicit sub-domain of OR for more than 30 years. In this paper, we briefly introduce its history and development before tackling the controversial issue of how it can be differentiated from other forms of OR. While it has been persuasively argued that Community OR cannot be defined by its clients, practitioners or methods, we argue that the common concern of all Community OR practice is the meaningful engagement of communities, whatever form that may take – and the legitimacy of different forms of engagement may be open to contestation. We then move on to discuss four other controversies that have implications for the future development of Community OR and its relationship with its parent discipline: the desire for Community OR to be more explicitly political; claims that it should be explicitly grounded in the theory, methodology and practice of systems thinking; the similarities and differences between the UK and US traditions; and the extent to which Community OR offers an enhanced understanding of practice that could be useful to OR more generally. Our positions on these controversies all follow from our identification of ‘meaningful engagement’ as a central feature of Community OR.