Although sleep disorders such as insomnia and obstructive sleep apnea are common in both children and adults, the clinical features and treatments for these conditions differ considerably between these two populations. Whereas an adult with obstructive sleep apnea typically presents with a history of obesity, snoring, and prominent daytime somnolence, a child with the condition is more likely to present with normal body weight, tonsillar hypertrophy, and inattentiveness during school classes. The adult with suspected sleep apnea almost always undergoes a baseline polysomnogram and proceeds to treatment only if this test confirms the diagnosis, while many children with suspected sleep apnea are treated empirically with adenotonsillectomy without ever receiving a sleep study to verify the diagnosis. This article reviews sleep disorders in children, with a particular focus on age-related changes in sleep, conditions that primarily affect children, and disorders for which clinical manifestations and treatment differ substantially from the adult population.