In a world where people interact across countries, citizens need to find their role in the global community; therefore, global citizenship (GC) has become an influential theme in higher education. Due to its various interpretations and modes of action, in this paper GC is addressed as a floating signifier. Our main data comes from interviews with ten academics from five UK universities that host internationalization programmes. The respondents were asked about the signified (in the Saussurian sense) that they attribute to GC, what skills are necessary to be a global citizen, and how the sciences contribute to the articulation of GC. Although showing different approaches to GC, academics agreed that the university is its main discursive context and that projects and programmes must involve all sciences in interdisciplinary relations.