City diplomacy between EU and Chinese cities has become an increasingly significant layer of bilateral relations. The collaboration between cities is extensive and covers a wide range of thematic areas, with around half of the European cities having partnerships with Chinese counterparts, according to a survey of 745 cities. However, despite the commonality of these partnerships, our research has highlighted a disconnection between subnational relations and the upper levels of European policy. Despite some previous initiatives, local actors have not been effectively engaged in the EU policy-making. The European Parliament has called for greater coordination with sub-state actors, but this call has gone unanswered. The paper unpacks the city level of EU relations with China, showing its scope, patterns of cooperation, and potential impact. The authors present theoretical and empirical arguments to support the notion that city diplomacy should have a much more significant impact on EU policy towards China.