Despite previous studies showing that children's development of executive function (EF) skills is associated with the differing contexts in which children live, evidence about the independent and synergistic effects of families and neighborhoods is limited. Using a sample from a two-cohort longitudinal study of preschoolers from low-income families, we examined whether residential neighborhood resources (measured with the Child Opportunity Index (COI)) moderated the relationship between family cumulative risk and the growth trajectory of children's EF skills. Results from conditional growth curve models indicate family cumulative risk was negatively related to baseline EF skills and the rate of EF skill growth. In contrast, the overall COI and the COI social and economic domain z-score were positively associated with the initial, but not linear, growth of EF skills. We found no evidence of moderator effects. Policies that aim to better target and support the most vulnerable children should consider the unique contribution of family risks and neighborhood resources to child development.