Background <p>The relationship between the parent–child relationship and adolescent depression is much discussed, but still not fully understood. Based on ecological systems theory, this study examined the potential mediating role of psychological resilience and the moderating role of school climate between the association of parent–child relationship and adolescent depression.</p> Methods <p>This study employed a three-wave longitudinal design with six months between each time point, involving 549 elementary and middle school students in southeastern China (50.82% males; mean age at Time 1 = 11.43). Measurements included the parent–child relationship (T1), psychological resilience (T2), school climate (T3), depression (T1 and T3), and demographic information.</p> Results <p>The moderated mediation model demonstrated that after controlling for baseline adolescent depression (T1), the parent–child relationship (T1) was longitudinally and negatively associated with adolescent depression (T3) through the mediating effect of psychological resilience (T2). Additionally, the analysis revealed that a positive school climate moderated this mediation by mitigating the adverse impact of low psychological resilience on adolescent depression, thus reducing the indirect effect of the parent–child relationship on adolescent depression.</p> Conclusions <p>Our findings offer a nuanced understanding of the underlying mechanisms linking parent–child relationship to adolescent depression among Chinese adolescents. Theoretical contributions and practical applications of these findings are further elaborated.</p>