Cities claim an ever-larger role in migration governance, often by means of progressive policies that “decouple” the local from the national. The literature on this “local turn” has generally failed to recognize how this decoupling increasingly takes place within the context of Transnational Municipal Networks (TMNs). On the basis of a database of the 20 most important TMNs in refugee and migrant welcome and integration in Europe and additional empirical research, this article identifies and analyzes their main characteristics, composition, and activities in a multiscalar context, thus contributing to a better understanding of migration governance. It argues that these networks, by means of a wide variety of activities, serve a practical but also a symbolic and jurisgenerative purpose. These implicit and explicit objectives of city networking also account for the proliferation of TMNs witnessed across Europe since 2015. In “teaming up,” European cities not only share practical experiences but also develop narratives about migration that counter national, more restrictive discourses and contribute to the global legal framework, as was the case with the Global Compact on Refugees and Migrants. It is this practical, symbolic, and jurisgenerative role of TMNs, in times of increasingly restrictive national policies, that makes these networks key actors in contesting but also improving global migration governance.