This working paper examines the literature on regional organizations’ humanitarian priorities and activities. It begins a fuller discussion of their tangible contributions to humanitarian action and reviews their work in three different areas: humanitarian assistance facilitation and delivery (particularly in relation to refugees), disaster risk reduction (DRR) and conflict management. Chapter 2 examines key concepts applicable to regional organizations, including foundational issues such as subsidiarity and sovereignty. Chapter 3 offers a short review of the emergence of regional organizations’ humanitarian institutions, and chapter 4 addresses an issue about which far less is known – the activities of regional organizations in crisis-affected contexts. Given the breadth of humanitarian action, this chapter focuses on assistance to refugee populations – given that they comprise a regional challenge – as well as DRR and conflict management. Then, wrapping up the discussion, chapter 5 presents a series of questions which have not yet been addressed within the existing literature on regional organizations’ role in humanitarian action. This paper is part of a broader Humanitarian Policy Group (HPG) project on the role of regional organizations in humanitarian action.