The centrality of metropolitan regions in policy and research does not mean they are perceived by their population as having a meaningful identity. This affects their political legitimacy, economic development prospects and place qualities. However, the ongoing scalar expansion of our spatial attachments creates the potential for a metropolitan identity, which can contribute to a stronger metropolitan region vision. As a component of identity formation, place naming becomes relevant both to represent and construct this scale. This article evaluates the geographical, institutional and social factors that shape naming processes in metropolitan regions undergoing integration. We consider historical examples representing different modes of name formation: New York, Stoke-on-Trent, Budapest, Charleville-Mézières, Metroplex and Thunder Bay. We find that metropolitan toponyms emerge from a nexus of interdependent factors, some of which decisively push naming processes into specific paths, and that such processes reflect the socio-political and cultural contexts shaping metropolitan regions. This provides a framework of questions that metropolitan institutions can consider to envision the names they are more likely to develop. [ABSTRACT FROM AUTHOR]