Based on the empirical research, the article considers the correlation of national and ethnic identities of the youth of Saint Petersburg. The authors' conclusions are based on a series of sociological studies conducted in 1996, 2011 and 2019 by the Laboratory of Ethnic Sociology and Psychology of the Faculty of Sociology of the Saint Petersburg State University under the guidance of Z.V. Sikevich and also on the data of other researchers studying similar issues in different Russian regions. The authors present their interpretation of the structure of national identity and typology of ethnic identities; consider the following forms of correlation of national and ethnic identities — dominant ethnic identity, ethnic radicalism, dominant national identity, ethno-national radicalism, ethnic and national indifference; focus on the rank of national identification in the system of group identities and on the indicators of national consolidation; use content analysis to identify the symbolic interpretations of the words 'Russia', 'citizen' and 'patriot'; analyze contradictions in the national identity of the youth. The article presents the following most important findings of the study: 1) national (civil) identity dominates other forms of social identification of the youth; 2) in the structure of social identities, confessional identity is insignificant, while there is negative distancing towards representatives of Islam; 3) ethnic and ethno-national radicalism is typical for men; 4) compared to 2011, the positive trend of statist attitudes and the negative trend of critical attitudes to power are obvious; 5) the perceived norm and attitudinal behavior of the youth are not quite consistent; 6) gender affects the level and type of both ethnic and national identity.