The chapter explores the regulation of professional tennis as a sub-species of transnational law and as part of the lex sportiva. It goes on to show how this transnational character plays out in disputes arising from regulatory matters and then moves on to ascertain the relationship among the three key tennis actors, namely the ITF, WTA and ATP. The chapter next explores the relationship between professional tennis and domestic law, including governance of the sport globally, as well as the relationship between national tennis federations and the ITF, and the latter’s relationship with the International Olympic Committee. The chapter further delves into the labor status of professional tennis players, as well as the relevance of international law in professional tennis, including the sport’s status in the Olympic Movement, as well as the human rights standard-setting role of transnational tennis entities.

This chapter aims to show that the work of the Court of Arbitration for Sport (CAS), which is often identified as the institutional centre of the lex sportiva, can be understood as that of a seamstress weaving a plurality of legal inputs into authoritative awards. In other words, the CAS panels are assembling legal material to produce (almost) final decisions that, alongside the administrative practices of sports’ governing bodies, govern international sports. It is argued that, instead of purity and autonomy, the CAS’s judicial practice is best characterised by assemblage and hybridity. This argument is supported by an empirical study of the use of different legal materials, in particular pertaining to Swiss law, EU law and the European Convention on Human Rights, within the case law of the CAS. The chapter is a first attempt at looking at the hermeneutic practice of the CAS from the perspective of a transnational legal pluralism that goes beyond the identification of a plurality of autonomous orders to turn its sights towards the enmeshment and entanglement characterizing contemporary legal practice.

This chapter reflects on the diversity of usages of the notion of transnational law in legal scholarship. To do so, it focuses on the lex sportiva as a fruitful empirical field to study in concreto the use of the concept. Indeed, the regulation of international sports is nowadays often referred to as lex sportiva and deemed an example of transnational law. The first part of this chapter retraces how lex sportiva has been used as empirical evidence for a ‘pure’ theory of transnational law, a conception of transnational law as denationalized legal order of a transnational community. The second part will aim to show how lex sportiva can also be used to support an ‘impure’ theory of transnational law, which might better capture the messy process of transnational interactions between multiple levels, norms and institutions that characterizes much of contemporary legal practice.