With the development of its common policy on transport, the European Union (EU) has been able to acquire an important part of its Member States’ jurisdiction in the aviation sector. However, despite its competence in the aviation sector, the EU currently has only an observer status within the International Civil Aviation Organization (ICAO). In fact, the provisions of the Convention on International Civil Aviation, which institute ICAO, only allow for sovereign States to accede to it. Therefore, this chapter discusses the representation of the EU at ICAO as well as in the multilateral air law instruments adopted under the auspices of the Organization. Additionally, examples of how ICAO and the EU have influenced each other in the development of policies will be highlighted.