Melatonin is an endogenous neurohormone that regulates the sleep-wake cycle (1). It is used therapeutically for insomnia in adults and for primary sleep disorders in children (2). Melatonin is regulated by the Food and Drug Administration (FDA) as a dietary supplement. Various synthetic melatonin preparations are widely available over the counter (OTC) in the United States with sales increasing from $285 million in 2016 to $821 million in 2020 (3). Children are at increased risk for melatonin exposure because of the supplement's widespread use and growing popularity as a sleep aid. In 2020, melatonin became the most frequently ingested substance among children reported to national poison control centers (4); however, more research is needed to describe the toxicity and outcomes associated with melatonin ingestions in children. This study assessed isolated melatonin ingestions among the pediatric population (defined here as children, adolescents, and young adults aged ≤19 years) during January 1, 2012-December 31, 2021, using the American Association of Poison Control Centers' National Poison Data System (NPDS). During the 10-year study period, 260,435 pediatric melatonin ingestions were reported to NPDS, and the annual number of ingestions increased 530%. In addition, pediatric melatonin ingestions accounted for 4.9% of all pediatric ingestions reported to poison control centers in 2021 compared with 0.6% in 2012. Pediatric hospitalizations and more serious outcomes due to melatonin ingestions increased during the study period, primarily related to an increase in unintentional ingestions among children aged ≤5 years. Five children required mechanical ventilation, and two died. Consumers and health care professionals should be encouraged to report any melatonin product-related adverse events to MedWatch, the FDA's medical product safety reporting program. Public health initiatives should focus on raising awareness of increasing numbers of melatonin ingestions among children and on the development of preventive measures to eliminate this risk.