Report. The presumption of innocence is a legal phenomenon that constantly attracts the attention of researchers. It is considered in legal science from the point of view of its origin, legal formalization, content and meaning. The interest in this problem is caused, on the one hand, by the multidimensional nature of this presumption, and, on the other, by its practical significance not only for society and the state, but, first of all, for a specific individual. The presumption of innocence is usually considered by specialists in the field of criminal law and criminal procedure, since, in their opinion, it belongs to the criminal sphere, the sphere of judicial proceedings, evidence. Meanwhile, such a view of the problem, it seems, limits the true essence of the phenomenon and reduces its significance.The purpose of this study is to substantiate the constitutional nature of the principle of the presumption of innocence.Research methodology. In this work, general scientific and private scientific research methods were used, such as analysis, synthesis, abstraction, and the case method.The results of the conducted research. As a result of the analysis, the author comes to the conclusion that the presumption of innocence is a constitutional principle. The constitutional nature of this phenomenon is inherent in its nature, sources, content, meaning. Conclusions. The presumption of innocence is a constitutional principle. Considering it exclusively through the prism of criminal law and criminal procedure, as an element of judicial proceedings related to the theory of evidence and the adversarial nature of the parties, greatly limits its role and significance, leads to too narrow an understanding of its content. The presumption of innocence is a legal phenomenon that affects various social relations, including those related to the electoral process, to administrative proceedings, to tax relations, etc. As a constitutional principle, the presumption of innocence interacts with other constitutional principles: the principle of the rule of law, the social state, the democratic state, freedom, equality, justice, legality, etc. The presumption of innocence expresses the balance of the public and private interests of a state-organized society. The existence of this one of the most important constitutional phenomenon shows the value of the individual in the legal system.