Civil society participation and mechanisms of societal access have been heralded as a possible solution to the legitimacy deficits faced by global governance institutions (e.g., stakeholder democracy). While much literature has examined the relationship between participation and legitimacy of international institutions, its application to courts has been largely ignored. Thus, the question remains how proposals for the participatory governance can apply to international courts and tribunals. How can international courts provide access to civil society, what is the quality of this access and can such access rectify the legitimacy challenges of international courts? This paper addresses these questions by exploring the ways in which international courts can incorporate civil society participation into the judicial process and what effects such participation can have on the legitimacy of international courts. I draw on a broad comparative analysis of international trade courts to build illustrate the relationship between access and legitimacy.