Abstract: In Europe, fundamental rights are enshrined in national constitutions, the EU Charter of Fundamental Rights, and the European Convention on Human Rights, which partly overlap but are not hierarchically ordered. In this context, the goal of this chapter is to provide a theoretical account of judicial dialogue as a source of legitimacy for the Court of Justice of the European Union in adjudicating fundamental rights. The prolific use of dialogue and similar notions has worked to mystify the meaning of dialogue. First, the diverse uses of dialogue in the EU academic literature will be examined. Next, the reasons for dialogue from a normative perspective will be spelled out in order to frame a theoretical account of judicial dialogue in the EU. Finally, I will respond to the challenges to judicial dialogue from the perspective of the opposition between strategic and dialogic action, and the adequacy of the preliminary reference as an avenue for dialogue.