In the wake of the Brexit referendum on Britain’s membership of the European Union of June 2016 the idea of a specifically British cosmopolitanism has come to the fore. Yet for much of the post-Second World War period it was a less familiar term than more typically British values of ‘tolerance’ or ‘respect’ towards immigrants, refugees or citizens of other countries. The term’s original meaning, derived from Greek κοσμοπολίτης or ‘citizen of the world’, combines the Greek word κόσμος for ‘world’ and πολίτης for ‘citizen’ to suggest a political ethos that moved beyond ties to the city-state or ‘polis’ to embrace commonalities with the wider world. Its English definitions pull in contradictory directions: on the one hand, describing people or species that transcend nationality, ‘Belonging to all parts of the world; not restricted to any one country or its inhabitants’; on the other hand, describing places often viewed with suspicion, ‘Composed of people from many different countries’. In an interview in 2006, Stuart Hall captured the ambivalence surrounding the term even for its advocates. Critiquing the impact of globalisation, he argues: ‘If we don’t move towards the more open horizon of cosmopolitanism-from-below, we will find ourselves driven either to homogenization from above or to the barrier of, the war of all against all.’ Yet when his interviewer, Prina Werbner, asks him, ‘Do you feel yourself to be a cosmopolitan?’ Hall pauses uncomfortably, ‘You know you hear me hesitate every time I use the word.’ Hall’s hesitation has to do with the idea’s origins in Enlightenment philosophy and ties with colonialism which excluded non-Western subjects. But his hesitation to invoke the term is typical in a British context, to do with its rarified or elitist connotations. Yet this ambivalence and global reach, this double quality of belonging out there in the world and bringing the whole world home to challenge local loyalties or identities, has made cosmopolitanism a rich source of fictional exploration. I will argue here that despite its utopian aspirations, cosmopolitanism is frequently a disruptive force in British fiction, producing disturbing scenes, narrative doubling and conflict, as often as it represents hospitable people and spaces or imaginary alternatives to provincialism, nationalism and xenophobia.