World Cities (or Global Cities) research has formed one of the most widely circulated strands of literature relating to contemporary urbanisation. It has been explored from increasingly diverse geographical perspectives and fortified by a range of theoretical and methodological positions. In the recent past, however, critical theorists have questioned the ‘World City’ concept's value, mustering a range of arguments pertaining to the reification of particular cities and structurally deterministic modes of thinking. In the same time frame, however, the concept has been widely appropriated in policy circles, leading to a host of political platforms positioning cities as ‘global’ through neoliberally oriented fast policy. This presents a curious divergence in which the policy community has placed increasing faith in the concept based on the perceived economic benefits of ‘global’ policy, while the academic community concurrently realises that new ways of understanding cities in a global context are necessary for complex international systems to be properly theorised. This paper addresses this juxtaposition, offering an ontology of four discrete agendas within the realm of World Cities. These are as follows: as a hypothesis for understanding the role of cities in the contemporary economy; as a label for cities with certain characteristics; as a new (meta) geography of cities; and as sites for understanding and studying globalisation. The purpose of this article is to delineate these so as to guide scholars and practitioners alike who find themselves inundated with publications that may in fact be discussing divergent concepts with the selfsame language. Within each respective agenda, new language is needed to guide policy conversations that are productive and specific and draw from new theory rather than relatively antiquated and generic ideals.