Obtaining and maintaining humanitarian access to populations in need by humanitarian actors is a challenge. A wide range of constraints on humanitarian access exist, including ongoing hostilities or an otherwise insecure environment, destruction of infrastructure, often onerous bureaucratic requirements, and attempts by parties to armed conflict to block access intentionally. The difficulties that these constraints present to humanitarians are frequently compounded by a lack of familiarity – on the part of states, non-state armed groups, and humanitarian relief organizations – with the legal framework. The main purpose of this article is to lay out the existing international legal framework regulating humanitarian access in situations of armed conflict.