When courts are faced with questions regarding the territorial scope of internal legislation, they are required to engage with controversial issues pertaining to the permissible boundaries of regulatory reach, which go beyond traditional conceptions of state sovereignty and non-intervention on which the functioning of courts is normally based. This Article examines the role of the Court of Justice of the European Union (‘CJEU’) in reviewing the legality and interpretation of the extraterritorial reach of EU environmental law, including animal welfare. It assesses the extent to which judicial review by the CJEU serves as a transnational mechanism for addressing legitimacy concerns raised by the unilateral exercise of EU regulatory power beyond EU borders.