The European Union Agency for Law Enforcement Cooperation (Europol) is competent to support action by the EU Member States’ law enforcement authorities and strengthen their cooperation in the fight against cross-border crime. Europol is not a ‘European FBI’ as it does not have executive powers. Nevertheless, its contribution to the activities of national police authorities is increasingly appreciated by practitioners, especially since the Agency is in an ideal position to process and exchange enormous amounts of personal data that are relevant for criminal investigations. This chapter examines Europol’s history, structure, competence and powers, as well as its relations with partners and the rules on its accountability. It also focuses on the crucial role that Europol plays in shaping EU criminal justice thanks to its Serious and Organised Crime Threat Assessments, which set in motion a process at the European level by which the EU periodically identifies its priorities for the fight against serious international crime (the Policy Cycle-EMPACT). This chapter also analyses the forthcoming revision of Europol’s legal framework, which aims to ensure that the Agency can efficiently perform its tasks in an ever-changing security landscape.