Background <p>Social media have become a central arena for identity construction, particularly for minority communities whose languages and cultures have been historically marginalized. Drawing on self-expansion theory, this study examines how social media facilitate language-based identity expansion within the Kurdish community in Türkiye. Despite long-standing suppression of the Kurdish language and culture, digital platforms provide new spaces for linguistic reconnection, cultural expression, and the reinforcement of collective identity. While self-expansion theory has traditionally focused on interpersonal contexts, little empirical research has examined identity expansion as a collective, language-centered process in digital environments.</p> Methods <p>An exploratory sequential mixed-methods design was employed. In the qualitative phase, semi-structured interviews with Kurdish participants informed the development of the <i>Scale of Language-Based Identity Expansion through Digital Media</i> (SLIEDM). In the quantitative phase, the scale was evaluated through exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). In Study 2, a cross-sectional survey tested associations between language-based identity expansion and key social-psychological variables, including group identification, life satisfaction, age, and patterns of language use on digital media.</p> Results <p>Factor analyses supported a unidimensional structure of the SLIEDM with strong psychometric properties. Quantitative findings demonstrated that engagement in one’s mother tongue on digital media was associated with language-based identity expansion and collective identification processes. Language-based identity expansion was positively associated with the use of Kurdish on digital media, in-group identification, and life satisfaction, whereas age was negatively associated with identity expansion. Group identification and native language use on social media emerged as significant predictors of identity expansion.</p> Conclusions <p>The findings indicate that social media function as a critical context for language-based identity expansion among marginalized groups. Digital engagement in one’s mother tongue supports language-based identity expansion by strengthening group identification and enhancing psychological well-being. These results extend self-expansion theory beyond interpersonal domains to collective, language-centered identity processes in digital environments. The study highlights the importance of language use in online spaces as a psychological and cultural resource for minority communities and provides a validated instrument for future research on identity expansion across diverse sociopolitical contexts.</p>