This chapter focuses on the shareholder and its increasingly important place in international economic law and, in particular, international investment law. The increasing importance of the place and role played by shareholders is a consequence of the increasing importance of multinational corporations on the international scene. The more pronounced place and role played by private actors on the international scene leads to the appearance of “new” real parties in interest. Because shareholders qualify as “investors,”,+ they are protected under international investment treaties and can have recourse to investor-state arbitration. As investors, the protection of shareholders in international investment law must be acknowledged in order to preserve the latter’s legitimacy. This chapter also identifies the different conflicts of interest which may exist among different categories of shareholders (minority and majority shareholders or foreign and domestic shareholders), as well as among shareholders and creditors. These conflicts of interest are important to understanding the dynamic at stake in shareholders’ claims for reflective loss and, in some instances, can justify shareholders’ claims for reflective loss in investment arbitration.