This thesis asks who is able to answer the call to action that the problems of global injustice pose. It focuses on the concept of institutions such as states, intergovernmental organisations, corporations and non-governmental organisations as moral agents and whether such institutions can be said to be morally responsible for creating or responding to global injustice. It examines three theories of institutional moral agency as presented by Peter French, Toni Erskine and Onora O’Neill and the way in which their conceptions of moral agency are based on the idea of attributing moral responsibility. It argues that the nature of organisational decision-making structures provides an unstable basis on which to establish the moral responsibility of institutions. It presents an alternative account of moral agency that includes institutions but separates the concept of moral responsibility from that of moral agency. The thesis contends that it is only individual agents who are able to bear moral responsibility, in the sense of blame or duty, for moral problems but that a coherent account of institutional moral agency is important for understanding the moral responsibilities of individuals in terms of the power of their collective actions. It argues that while institutions are capable of responding to the call to action that global injustice poses,  it is individuals who bear a moral responsibility to do so.