In view of recent articles citing the Stoics as a defence or refutation of cosmopolitanism it is legitimate to ask whether the Stoics did in fact have an argument for cosmopolitanism which may be useful to contemporary political philosophers. I begin by discussing an interpretation of Stoic views on cosmopolitanism by Martha Nussbaum and A.A. Long and show that the arguments they attribute to the Stoics are not tenable in the light of present day philosophy. I then argue that the Stoics did offer a very different argument for cosmopolitanism which is both more interesting and more plausible in that it draws on a conception of human nature similar to Aristotle’s and contemporary virtue ethics. Lastly I consider an objection made to their particular brand of cosmopolitanism by Martha Nussbaum, namely that a Stoic cosmopolitan life is devoid of personal affiliation and therefore unbearably lonely. I argue that this objection is in fact unfounded.