It is said that ‘not many fields of law use comparative law as extensively as international arbitration’ (Vadi, 2010). Indeed, comparative approaches to international arbitration law have assumed greater importance in the study of both commercial and investment arbitration. This chapter explores the applications of comparative law methods in the developments of international arbitration law, reviews their key contributions, and suggests potential directions for future study. These methods, whether traditional, historical, linguistic, socio-legal, empirical, or economic have all been employed to varying degrees and varying effects in the study of international arbitration law. Drawing from key publications in the field, this chapter will explore the research focus, themes of enquiry, organisational structures, and analytical techniques of each method in turn as applied to comparative arbitration studies.