<p>Cyberbullying poses a significant challenge for adolescents, making it essential to understand how various socialization contexts interact to influence victimization. Grounded in a socio-ecological framework, this study examined the relationship between parent–child interactions and cyberbullying victimization among middle school students. In addition, we investigated whether psychological capital (i.e., hope, optimism, self-efficacy, and resilience) and rejection sensitivity act as parallel mediators and whether a positive school climate moderates these mediation effects. Data were collected via anonymous questionnaires from 1,340 adolescents (<i>M</i>_age = 13.85, <i>SD</i> = 1.64) across four middle schools. Results revealed that favorable parent–child relationships were directly associated with reduced cyberbullying victimization. Moreover, higher psychological capital and lower rejection sensitivity partially mediated this relationship. Notably, a positive school climate moderated these mediating pathways by strengthening the link between parent–child relationships and reduced rejection sensitivity while attenuating the protective influence of psychological capital on cyberbullying victimization. These findings highlight the importance of integrating family and school-based strategies in anti-cyberbullying interventions, particularly for adolescents from disadvantaged family environments.</p>