Why is it that humanitarianism and theories of global justice seem to have relatively little engagement with each other? This article discusses some of the reasons for this being the case, and argues that instead of seeing these two fields as separate or adversarial they should be viewed as complementary. The article begins with a brief overview of humanitarianism, in order to argue for the relevance of justice in humanitarianism. The second section focuses on analyzing selected theories of justice— those of Peter Singer, John Kekes, and Thomas Pogge—through a particular lens, that of the question of responsibility for global well-being. The article concludes by arguing that theories of global justice can be beneficial for humanitarian causes, not in a comprehensive and consistent “all-or-nothing” manner, but rather on a case-by-case basis and through selective application of particular arguments.