This study explores the transformations in high school students’ self-perception as global citizens in the city of Rasht, Iran. Globalization, as a socio-cultural phenomenon, has reshaped the values, attitudes, and identities of younger generations, confronting them with new challenges in redefining citizenship. The objective of this research is to examine the various dimensions of these identity shifts and analyze adolescents’ lived experiences in the context of globalization. The study was conducted using an ethnographic qualitative approach. Data were collected through semi-structured interviews with 15 male and female students in grades 10 to 12 (aged approximately 15 to 18) and through participant observation in school settings. Thematic analysis was applied to analyze the data. The findings revealed that globalization affects students’ identities in five major dimensions: globalization of everyday experiences, globalization of values, development of critical consciousness, sociocultural transformation, and increased emphasis on individual selfhood. These dimensions indicate that adolescents are not merely passive recipients of global influences, but rather actively reconstruct their personal and social values toward forming transnational identities. Tendencies toward independence, shifting reference groups, and critiques of educational and cultural structures were also observed. Overall, the study demonstrates that globalization is a multifaceted and complex process that deeply impacts all aspects of adolescents’ lives, leading them toward a redefined understanding of the self as a global citizen.