As sports markets become more integrated and international corporations or organizations increasingly dominate national and transnational competitions, the role of the state in the governance and regulation of such entities increases. Sports competition is no longer limited to competition amongst clubs within the same league but also includes competition in terms of viewership, engagement, sponsors, and revenue amongst leagues (within the same sport or even across sports). The significant impact of successful sports competitions on economic development has motivated states to become more actively involved in the organization of sports competitions. As international trade and investment in the sports industry increases, the impact of state actions in regulating their domestic sports market and sports actors, including players, media companies, and associations, becomes increasingly impactful. The increasing role of trade and investment rules is exemplified through the various complaints at the European Commission under the Foreign Subsidies Regulation for distortion of EU football competition due to foreign subsidies being injected into football clubs. This chapter explores the intersection between international economic law, specifically trade and investment law, and sports law by analysing instances of alleged discrimination between foreign and domestic players, foreign and domestic broadcasters, foreign investors in domestic clubs, and foreign or foreign and domestic sports competition organizers. The chapter examines recent developments in the European sports industry, such as the European Super League and the potential investment of non-European actors in the basketball league (Euroleague), as case studies for the application of international trade and investment rules. In particular, it assesses how specific rules existing in various European sports markets, such as the ‘home-grown players’ rule, the various qualifying offers rules (e.g., Spanish ‘Tanteo’ Rules—right of first refusal), the FIFA ‘player loan’ rules, financial fair play rules, and competition regulation, interact with international trade and investment rules. The chapter seeks to engage with the latest sports competition developments and how international economic law norms will increasingly be interrelated with them.