We assess how immigrant parent legal status shapes children’s physical and mental health. Using the Hispanic Community Health Study of Latino Youth—a multi-site dataset—we evaluated mean differences in multiple physical and mental health indicators and parents’ and children’s stress and resilience by parents’ (primarily mothers’) legal status (N = 1177). We estimated regression models of two overall child health outcomes—allostatic load and any internalized disorder. Average allostatic load was 28% higher (0.36 standard deviations) and average prevalence of any internalizing disorder was 16% points greater for children of foreign-born unauthorized versus US-born parents. Higher levels of socioeconomic and acculturative stress contributed to children of foreign-born unauthorized parents’ heightened health risk, while resilience factors—parental health and familial support—protected their health. Children with unauthorized immigrant parents experience both negative physical and mental health outcomes that can have potential long-term costs.