According to the Guiding Principles on Internal Displacement, Internally Displaced Persons (IDPs) are persons who have been forced or obliged to flee or leave their homes or places of habitual residence for reasons such as violence, human rights violations, and disasters, and who have not crossed an internationally-recognized state border. Internal Displacement has been on the international agenda for decades, and yet it has received significantly less attention in legal literature than other categories of vulnerable individuals. This is particularly so in respect of the IDP description. There are countless works that analyse in rigorous detail the definitions of other categories of forced migrants, such as refugees, or trafficked persons, for example, but we have significantly less knowledge on what it means, in legal terms, to be an IDP.We have even less knowledge on who is excluded from the IDP description. Is an individual who has committed murder, aggression, and/or terrorism offences excluded from being an IDP? The key framework for the protection of IDPs—the Guiding Principles on Internal Displacement—does not address this issue and neither does scholarship. This can be contrasted to refugee law, where there are explicit clauses in the 1951 Refugee Convention as well as many analyses in scholarship ascertaining who is excluded from refugee status. This article therefore aims to answer the following question: Should there be exclusionary criteria regarding the IDP description? Answering this question is important because it will give us greatly-needed clarification on who counts—and who does not count—as an IDP.The article will proceed as follows: the introductory section sets out the article’s aims, structure, and contribution to literature. Part 2 will explain the article’s significance and Part 3 will briefly explain who an IDP is to provide a better understanding of whether anyone should be excluded from the IDP concept. Part 4 will examine whether exclusion clauses make sense in the IDP context, drawing on insights from the three branches of law which have inspired and/or formed the basis of the Guiding Principles on Internal Displacement: international refugee law, international human rights law, and international humanitarian law. Part 5 will conclude.