Context and Relevance. Prosocial behavior, defined as actions aimed at benefiting other individuals, groups, or society as a whole, is associated with a range of positive social outcomes, from strengthening a positive self-image to enhancing intragroup cohesion. Readiness to engage in prosocial actions is mediated by social identification and reflects the ways in which individuals define themselves across different social contexts in relation to members of various social groups. The nature of this relationship may vary across age groups and undergo particularly pronounced changes during youth. However, in the Russian context, there is a lack of comprehensive studies examining the transformation of the relationship between social identities and prosocial behavior. The relevance of this research is determined by the increasing differentiation of environmental factors, which necessitates the study of conditions enabling successful social integration and the formation of positive behavioral models. Objective. To examine the nature of the relationship between different forms of identity and prosocial behavior across various age groups within the contemporary Russian youth population. Hypotheses. It is hypothesized that (1) the prosocial behavior of youth is primarily associated with broad group identities, and (2) as youth mature, the relationship between prosocial behavior and personal identity becomes stronger. Methods and Materials. The overall sample consists of 355 Russian citizens aged 18 to 35. The following instruments were used: the abbreviated version of the Cheek and Briggs “Aspects of Identity” questionnaire; McFarland’s “Identification with All Humanity” scale; Carlo and Ran-dall’s “Prosocial Tendencies Measure”; and a socio-demographic indicators survey. Hypotheses were tested using one-way analysis of variance (ANOVA) and regression analysis. Results. Differences were identified in the structure of relationships between identity and prosocial behavior among different age groups. With increasing age, the number of prosocial behavioral forms associated with civic identity expands. In addition, the relationship of relational identity to conformist and altruistic forms of prosociality changes; a connection with personal identity emerges. Conclusion. It is advisable to study “youth” as a differentiated group, considering the dynamic transformation of their socio-psychological characteristics depending on the social situation of development. As individuals age, the connection between prosocial behavior and personal structures reflecting group experience grows stronger; later, orientation toward personal goals and values is added to these structures