Since the adoption of the principles of the Responsibility to Protect (r2p) in 2005, proponents and critics alike have accepted that it has not brought about a consistent and effective response to mass atrocity crimes. The incapacity that the Security Council exhibits in addressing the Syrian conflict provides a compelling justification for the need to examine alternative mechanisms through which the principles of the doctrine can be implemented. This paper argues that regional organisations should be considered legitimate authorising mechanisms in place of the Security Council in implementing r2p. The use of regional institutions as authorising mechanisms has not been properly considered or rigorously defended. In the paper, I make a case for regional organisations in authorising international action during mass atrocity situations by first establishing the legitimacy of regional organisations to act in response to local disputes. I propose and defend four arguments that provide justification and establish the utility of regional arrangements as alternative authorising mechanisms. I also examine and respond to three key objections that can be made against regional organisations. Finally, I outline a set of criteria that should determine which regional organisations are considered legitimate actors during mass atrocity situations.