|Cultural diplomacy as discourse and practice looms large today in both cultural policy studies and international relations. In effect, the term cultural diplomacy is widely used, so much so that it has become a floating signifier, commonly deployed by foreign policy establishments and the arts and culture sector alike (Isar 2010). Cultural diplomacy has become an ambivalent concept with blurred boundaries. A more traditional definition of cultural diplomacy sees it as a soft power tool through which states and/or international organizations pursue foreign policy objectives. Cultural diplomacy in this perspective would be limited to the processes that occur when formal diplomats, operating at the service and in the name of their governments, use cultural resources to help advance national interests. But in recent years, an expanded and more self-reflexive definition has prevailed which conceives it as a policy area in its own right, which promotes quality of life, the arts, joint capacity building, economic growth and social cohesion by engaging citizens and civil society actors, across borders, both as producers and consumers of cultural activities. This expanded definition of cultural diplomacy uses exchanges of cultural goods and services, cooperation and networking among museums, cultural foundations and ministries, artists and curators from different countries and continents, to promote better and closer relations and extend their overall societal and political influence. Even in this extended form though, cultural diplomacy activities may also be used to advance specific geopolitical interests or to buttress trade policy (Ang et al. 2015). Earlier, the two definitions and the processes related to them were seen as distinct by analysts. The former was defined as cultural diplomacy and the latter as international cultural relations, which remain based on flows of cultural exchange but take place naturally and organically, without government intervention. As the distinction has become blurred both in policy and scholarship, the attention of researchers has remained directed mainly at exchanges between countries and at cultural programmes and overall cultural activities taking place between and among nation states. This form of ‘methodological nationalism’ has led to two major lacunae, both of which merit further debate and research. The first of these is that there is very little direct analysis of the motivations, values and efforts of civil society actors. The second is the relative absence of research on how cities are now practicing international cultural relations and diplomacy among themselves―and they are often doing this via the agency of civil society actors. With a view to addressing these interconnected gaps, a workshop was organized by the guest editors at the Robert Schuman Centre for Advanced Studies at the European University Institute, Florence, Italy, on 21 May 2019. This was a point of departure. This special issue now brings together the contributions made to that discussion and that have been further developed by eight authors.