The article is devoted to consideration of the terms «person of a criminal» and «personality of a criminal» used in criminology. It is noted that criminology is a science, mostly social, and therefore less dependent on the formation of its terminology from the terms used in the text of the law. Attention is drawn to the fact that the term «personality of a criminal» is a term based on criminology, which causes increased attention to it. It is argued that it is the unification of terminology, the provision of criminological terms of unambiguity and generality that will make criminological research effective, will protect researchers from logical errors. In this regard, it is proposed to consider the expediency of using the term «personality of a criminal» in criminology. The focus is on changes in the criminal legislation of Ukraine in 2020, according to which the content of the term «crime» has changed significantly. In this regard, the question is considered: whether it is possible to continue to speak about the «person/personality of a criminal», whether it will be more appropriate to use the term «person/personality of a criminal offender». On the basis of logical assumptions, the conclusion is made about the possibility of operating in criminological investigations in terms of «crime» and «person of a criminal». Attention is paid to the fact that in scientific publications of Ukrainian criminologists the term «person of a criminal» and the term «personality of a criminal» are used. It is concluded that such duality is the result of a false translation of the Russian term «identity of a perpetrator». It is noted that most authors who use the term «person of a criminal» consider a set of physiological characteristics of a person prone to criminal offenses of a certain kind, and therefore — we are talking, rather, about «personality», not «person». At the same time, it is emphasized that the term «person of a criminal» is common, and therefore this should not cause any discussions or problems with the correct understanding of its essence in criminological studies. In this regard, the conclusion is made about the possibility of using the formally incorrect term «person of a criminal» as synonymous with the term «personality of a criminal».