This paper explores the concept of cyber boundaries and sovereignty as reflected in the cyber national strategies documents of European Union (EU) member states. The study seeks to provide an overview of how different EU member states approach and define these concepts, and to determine the extent to which they are reflected in national cyber strategies.The study provides an overview of the different approaches to defining and conceptualizing cyber boundaries and sovereignty and examines how these concepts are reflected in the cyber strategies of EU member states. Through a comparative analysis of the cyber strategies of selected EU member states, the paper identifies key themes and trends of cyber boundaries and sovereignty in EU members. The paper also examines the potential implications of cyber boundaries and sovereignty for the EU's broader cyber policy framework and the challenges this poses for cross-border cooperation in cyberspace.Overall, this paper argues that while cyber boundaries and sovereignty remain contested concepts in the EU, they play an important role in shaping national and EU-level cyber policy, and as such, a deeper understanding of these concepts is essential for effective cyber governance in Europe.