Based on the scholarly discussions about interregionalism, this chapter argues that the development of relations between the EU and the CAN may be understood conceptually from the different typologies of interregionalism at all levels (pure, hybrid, and transregional) and addresses the initiatives the EU and the CAN have undertaken in the last four decades to launch and consolidate bi-regional governance mechanisms. After providing an overview of the theoretical interpretations of the EU-CAN relationship, the chapter explores its evolution by identifying the demands for interregional governance and the different levels and issues in which both parties are implementing governance initiatives. Finally, the progress and setbacks of the governance mechanisms adopted by the EU and the CAN in the indicated period are analyzed, and the prospects for future development of interregional governance between the parties are presented.