In a post-Cold War era characterised by globalisation and deep interdependence, the actions of national governments increasingly have an effect beyond their own territorial borders. Moreover, key agents of global governance – international organisations and their bureaucracies, non-state actors and private agents – exercise pervasive forms of authority. Due to these shifts, it is widely noted that world politics suffers from a democratic deficit. This article contributes to work on global democracy by looking at the role of international courts. Building upon an original dataset covering the 24 international courts in existence since the end of the Second World War, we argue that international courts are able to advance democratic values and shape democratic practices beyond the state. They can do so by fostering equal participation, accountability, and public justification that link individuals directly with sites of transnational authority. We contend that the ability of international courts to promote these values is conditioned by institutional design choices concerning access rules, review powers, and provisions regarding judicial reason-giving. We canvass these design features of different international courts and assess the promises and pitfalls for global democratisation. We conclude by linking our analysis of international courts and global democratisation with debates about the legitimation and politicisation of global governance at large.