BACKGROUND AND AIM: While there is evidence that parks support pediatric health, there have been no national studies looking at both physical and mental health. We assessed whether the presence of a neighborhood park is associated with pediatric physical or mental health or health behaviors across the wider United States. METHODS: Hypotheses about child health and neighborhood parks were investigated among respondents to the National Survey of Children’s Health (NSCH) 2016, a nationally representative sample of children and adolescents aged 0-17. Caregivers reported on the presence of parks or playgrounds in the neighborhood and diverse outcomes, including child physical activity, screen-time, sleep, weight, and diagnosis of anxiety, depression, or attention deficit/hyperactivity disorder (ADHD). Covariates included child and family socio-demographics and, for 29 states, neighborhood urbanicity. RESULTS:Caregivers reported on 49,146 children (mean age 9.4 years; 49% female). There were 11,791 (24%) children living in neighborhoods lacking a park; children in non-urban locations (aOR 2.19, 95%CI 1.40–1.67) or below the federal poverty level (aOR = 1.48, 95%CI 1.38–1.58) had higher odds of lacking a park. Irrespective of socio-demographics, children lacking parks were more likely to be physically inactive (aOR1.36, 95% CI 1.24, 1.48), have excessive screen-time (aOR = 1.19, 95% CI 1.14, 1.25), or obtain inadequate sleep (aOR = 1.23, 95% CI 1.18, 1.29). Children without parks were more likely obese (aOR = 1.32, 95% CI 1.21, 1.43), overweight (aOR 1.25, 95%CI 1.17, 1.33), or diagnosed with ADHD (aOR 1.20, 95% CI 1.12,1.29), but not more anxious or depressed (aOR = 1.04, 95%CI 0.97, 1.11). CONCLUSIONS:Associations between parks and pediatric physical and mental health and health behaviors suggests that the provision of neighborhood parks could represent a low-cost childhood health intervention. KEYWORDS: Built environment, Green space, Children's environmental health, Mental health outcomes, Environmental disparities