Human dignity has been the foundational principle of choice of both international human rights law and domestic constitutional rights provisions since the end of the Second World War. However, in spite of widespread international agreement on the importance of the principle, there is a significant degree of confusion regarding what it demands of law makers and adjudicators, and considerable inconsistency in its formulation and application in domestic constitutional law. This paper will argue that much of this confusion stems from loose usage of the term by judges and commentators. The discussion will focus on two characterizations of human dignity frequently seen in domestic constitutional law which cannot be logically reconciled with its role in international human rights law: the idea of a right to dignity, and the related confusion between the concept of dignity and the right to personal autonomy. It will be argued that a move away from these characterizations of dignity would render the principle a more workable and useful tool as a foundational principle of constitutional rights.