The article is devoted to the evolution of the concept of dignity in ethical and philosophical thought. On the basis of the etymology of the word, the author reveals the basic definition of dignity as a measure of the correspondence of a person’s behavior to his or her position in society and the approving reaction of the others to such behavior. This definition is corrected in the analysis of the views of Aristotle, the Stoics, Cicero, Thomas Aquinas, J. Manetti, J. Pico della Mirandola, T. Hobbes, J.-J. Rousseau, I. Kant, and others. It is shown that in the course of historical development (under the influence of philosophy and religion) the hierarchical understanding of dignity was gradually replaced by the universalist one. Analyzing the notions of dignity as a theoretical foundation of the human rights system and disputes about dignity in contemporary bioethics, the author concludes that dignity is an important personal and social value, which potential in solving complex ethical dilemmas of present time, despite the frequent use of this word in public discourse, is not yet fully realized.