The article is devoted to the theoretical analysis of stigmatization as one of the tools of populist political discourse. Social stigmatization is defined as the process of marking a group of people on the basis of a certain characteristic, mostly under the influence of negative stereotypes. The mechanism of social stigmatization as a cognitive construct is revealed using the theses of D. Unadze's attitude theory. It is substantiated that stigmatization is a negative social attitude that carries biased information about a person, due to which all other qualities of his personality that do not cohere with the general stereotype are ignored. It is emphasized that the key role in the formation of stigmatizing attitudes in the socio-political discourse is played by values, in relation to which a consolidating value paradigm acceptable to the vast majority of citizens has been achieved. It has been proven that stigmatization is used primarily as the imagined method of protection of social values and norms, a kind of threat prevention mechanism that can hinder the effective unification and functioning of social groups. It is shown that the basis of the functioning of the stigmatizing attitude in political discourse is the imaginary division of social groups according to value through a kind of division according to belonging – into «Us» and «Them», cognitive separation of the branded social group and the perception of it as a hostile «Other». Emphasis is placed on the relevance of the study of stigmatization processes in the context of the modern Russian-Ukrainian war. It is substantiated that the stigmatization of social groups based on regional characteristics, rationalized in the populist discourse, complicates the dialogue and consolidation of Ukrainian society, as well as the future process of reintegration of temporarily occupied territories. The leading role of state bodies and institutions of civil society in promoting the process of consolidation of Ukrainian society and counteraction to stigmatization is emphasized.