The notion of digital sovereignty, also often referred to as technological sovereignty, has been gaining momentum in the European Union’s (EU) political and policy discourses over recent years. Digital sovereignty has come to supplement an already substantial engagement of the EU with the digital across various security policy domains. The goal of this article and of the overall Special Issue is to explore how the discourse and practices of digital sovereignty redefine European security integration. Our core argument is that digital sovereignty has both direct and indirect implications for European security as the EU attempts to develop and control digital infrastructures (sovereignty over the digital), as well as the use of digital tools for European security governance (sovereignty through the digital). It is thus essential to further explore digital sovereignty both in terms of European policies and of a re-articulation of sovereign power and digital technologies – what we suggest calling digital/sovereignty.