Abstract This article starts from the assumption that the future Multilateral Investment Court (MIC) will be shaped by a new and different type of international investment adjudicator (IIA) and focuses on the diversity issues that will need to be addressed during the Court’s creation. In this article, diversity is understood in a broad sense that includes questions related to IIA gender, race, geographical origins and legal background. The article argues that diversity may in fact evolve into one of the MIC’s key collective composition rules. It also sets out some of the grounds in favour of diversity in the MIC, and considers the specific ways in which diversity may permeate the constituent process for the MIC roster and its subsequent modus operandi. A further common thread is provided by the links between diversity and the principle of independence and impartiality, which will be a crucial MIC duty.