<p>Family conflict is a prevalent source of stress in children’s lives and has important implications for child mental health, particularly when conflict is severe and destructive. Prior research has documented associations between conflict within specific dyadic relationships, such as interparental or parent-child conflict, and children’s internalizing problems; however, less attention has been paid to conflict at the level of the overall family system and how multiple parental processes jointly shape this relationship. This study aimed to examine the effect of family conflict on children’s internalizing problems and to investigate whether parental psychological distress and harsh parenting serve as mediating mechanisms. Using a nationally representative sample of Singaporean children (<i>N</i> = 3964), we constructed a serial mediation model to assess the direct and indirect pathways linking family conflict to children’s internalizing problems via parental psychological distress and harsh parenting. Results showed that family conflict was significantly associated with children’s internalizing problems (b = 0.026, 95% CI [0.008, 0.043]). Parental psychological distress (b = 0.012, 95% CI [0.007, 0.018]) and harsh parenting (b = 0.006, 95% CI [0.002, 0.010]) each mediated this association, accounting for 26.67% and 13.33% of the total effect, respectively, and also operated sequentially (b = 0.001, 95% CI [0.000, 0.002]). These findings underscore the psychological burden of destructive family conflict on children and highlight modifiable parental processes as key pathways through which family adversity may affect child mental health. They also point to the importance of early, family-centered interventions that support parental emotional well-being and promote adaptive parenting practices to mitigate risk transmission.</p>