Abstract <p>The relationship is examined between the concepts of <i>ethnos</i> and <i>language</i> in the context of ethnic self-identification, where an individual’s perceived affiliation with a particular ethnic group is not supported by a connection to an equivalent linguistic (linguoethnic) characterization. The material used is data obtained through surveys, as well as ethnographic descriptions of the relationship between linguistic and ethnic self-identification in various countries. The study utilizes a correlation analysis method, aimed at establishing the relationship between linguistic and ethnic self-identification; a sociolinguistic interpretation method; and a sociolinguistic reinterpretation method, used in the sociolinguistic analysis of secondary, i.e., previously described, factual material. The linguistic (linguoethnic) identification of an ethnic nation is recognized as the foundation of identification processes, shaping ethnographic (subethnic), socioethnic, and ethnopolitical unity. Four situations of conjugation between ethnic self-identification and linguoethnic identification are identified: a situation of ethnic transition, when a person who defines him-/herself as belonging to a socioethnic group “by blood” linguoethnically identifies him-/herself with another ethnic group; a situation of subethnic transition, when an ethnic subgroup identifies itself as part of a nation using the regiolect or dialect of that nation; and two situations of ethnopolitical identity: first, when nationality is determined by a political factor, citizenship, while preserving the language of a linguoethnic group living in another, base state; and, second, when several ethnic nations—speakers of different languages—unite within a single political nation. This interpretation of the “ethnicity–language” relationship can be used as a basis for adjusting the parameters of sociolinguistic and social stratification of society.</p>