Objectives The COVID‐19 pandemic has tremendously impacted the U.S. healthcare system, but no study has examined the impact of the pandemic on utilization of dental care among U.S. children. Changes in past‐year dental versus medical visits and perceived unmet health needs between 2019 and 2020 among U.S. children aged 1–17 years were examined. Methods National and state representative, cross‐sectional data from the National Survey of Children's Health conducted during June 2019–January 2020 (i.e. pre‐pandemic, n = 28 500) and July 2020–January 2021 (i.e. intra‐pandemic, n = 41 380) were analysed. Any past‐year visit and perceived unmet needs (i.e. delay or inability to receive needed care) were reported by the parent proxy. Weighted prevalence estimates were compared using two‐tailed chi‐squared tests at p < .05. Poisson regression analyses were used to explore the relationship between having dental and/or medical unmet needs during the pandemic and indicators of poor health and social wellbeing. Results Between 2019 and 2020, a significantly reduced prevalence of past‐year medical (87.2%–81.3%) and dental visits (82.6%–78.2%) among U.S. children aged 1–17 years (all p < .05) were observed. Correspondingly, perceived unmet needs increased by half for dental care (from 2.9% in 2019 to 4.4% in 2020) and almost one‐third for medical care (from 3.2% to 4.2% in 2020). Subgroups with the highest prevalence of unmet dental need included those with low socio‐economic status, living with their grandparents, uninsured and living with a smoker. Conclusions Unmet health needs increased in general but increased more for dental than for medical care among U.S. children aged 1–17 years. Enhanced and sustained efforts will be needed to deliver targeted services towards disadvantaged segments of the population to narrow existing disparities.