Several important legal features of the contemporary practice of international organizations (IOs) are not easily accommodated in standard approaches to international organizations law. This article argues that Global Administrative Law (GAL) approaches may strengthen analysis of operational issues such as emergency actions by IOs and the human rights implications of IO activities, structural issues such as the involvement of IOs in field missions and in public-private partnerships, and normative issues concerning the production and effects of non-treaty regulatory instruments by IOs (guidelines, best practices, national policy assessments, and other documents rather amorphously analyzed under the 'soft law' rubric). In examining these activities as forms of administration (broadly understood), subject to precepts of good administration and legal standards concerning transparency, participation, reason-giving, review, and accountability, a GAL perspective provides a basis both for critique of problematic practices, and for increasing the effectiveness and legitimacy of some beneficial IO activities which are contentious or currently not undertaken. GAL also responds to the proliferation and differentiation of IOs and other entities in global governance through applying legal standards to their interactions, bringing a principled 'inter-public' approach to the legal relations among global public entities. GAL provides a valuable, and thus far overly neglected, addition to the field of international institutional law.