In the context of rapidly increasing digital consumption, this study investigates the impact of social media addiction and electronic word-of-mouth (eWOM) on compulsive buying behavior among sports consumers. Drawing on the Stimulus–Organism–Response (S-O-R) model and Social Identity Theory, the research proposes a comprehensive framework in which materialism and sports passion act as mediators. Data were collected from 293 individuals who have previously purchased sports products online and are active social media users. Partial Least Squares Structural Equation Modeling (PLS-SEM) was used to test the proposed hypotheses. The findings reveal that both social media addiction and eWOM significantly increase materialistic tendencies, which in turn drive compulsive buying behavior. Additionally, team identification enhances sports passion, which also mediates the relationship between identification and compulsive consumption. The results provide new theoretical insights into the psychological mechanisms behind impulsive buying in the digital age and offer practical implications for sports marketers seeking to manage consumer behavior more ethically in online platforms.