We examined whether parental social competence in adolescence was associated with parent–child bonding and, by extension, offspring’s social competence in childhood. Using a sample of prospective data collected over two decades from n = 473 parents (70% mothers) with n = 742 children (52% girls) who participated in the TRacking Adolescents’ Individual Lives Survey (TRAILS) cohort and its next-generation spin-off study (TRAILS NEXT), we modelled links between parental social competence at age 11, parent–child bonding when offspring were 3 months old, and offspring’s social competence at 30 months old. Adolescents’ assertion and cooperation were linked to parent–child bonding 20 years later. Parental assertion, but not cooperation or self-control, indirectly predicted offspring social competence via parent–child bonding. We found no evidence for intergenerational continuity of social competence in form of a direct effect. The results suggest that parent–child relationship quality predicts offspring’s social competence better than parents’ social competence but origins of variance in the latter partly precede parenthood.