Poor mental health among parents or primary caregivers is associated with poor mental and physical health in children; however, research often excludes the mental health of male caregivers including fathers. This analysis examines associations between caregiver mental health by caregiver sex and child health indicators (i.e., child's general health; child's history of diagnosed mental, behavioral, or developmental disorders (MBDDs)). Using parent-reported data on 97,728 US children aged 0-17 years from the National Survey of Children's Health (2016-2018), we estimated nationally representative, weighted proportions of children with parents or primary caregivers with poor mental health by caregiver sex, prevalence ratios (PR), and 95% confidence intervals (CI) for child health indicators by caregiver mental health and sex. Nationally, 7.2% of children had at least one caregiver with poor mental health; 2.8% had any male caregiver; and 5.1% had any female caregiver with poor mental health. Compared to children with all male caregivers with good mental health, children with any male caregiver with poor mental health were more likely to have poor general health (PR: 4.9, CI: 3.0-8.0) and have ≥1 diagnosed MBDDs (PR: 1.9, CI: 1.7-2.1); this remained significant when controlling for caregiver and household characteristics. Findings were similar when comparing children with any female caregiver with poor mental health to children with all female caregivers with good mental health. Our findings support previously published recommendations that promoting mental health among all types of caregivers by addressing gaps in research on fathers and male caregivers may further promote child health and wellness.