Social bonds and supportive relationships are widely recognized as being indispensable to healthy psychological functioning and well-being. Social support is a psychological resource that is expected to also contribute positively to parenting practices. The present study longitudinally examined the relations between mothers' (N = 674) and fathers' (N = 430) perceived social support and parenting behaviors, and their relations with children's social competence during early adolescence in Mexican-origin single and two-parent families. Our constructs of interest (warm parenting, monitoring, perceived social support, and children's social competence) were significantly correlated at T1, and demonstrated significant stability across time for both parental models. Parental warmth (as reported by the child, and opposite parent) and parental monitoring (self-reported by mothers and fathers) were correlated and also showed bidirectional associations across time. Parental monitoring at T2 positively predicted change in children's social competence at T3 (controlling for T1 social competence) for mothers. Parental warmth at T2 positively predicted change in children's social competence at T3 (controlling for T1 social competence) for fathers. For mothers, the indirect effect of social support at T1 on children's social competence at T3 via parental monitoring at T2 (and controlling for prior levels) was significant. Findings suggest that maternal perceived social support contributes to children's social competence due to its positive relation to maternal monitoring. Results may also suggest that mothers' and fathers' parenting behaviors differentially relate to children's social competence in Latino families, although additional work focused on comparing parenting behaviors in two-parent families is needed.