Much contemporary research has demonstrated the multiple ways that sleep is important for child and adolescent development. This article reviews that research with an emphasis on how sleep parameters are related to school adjustment and achievement. Five areas of sleep research are reviewed to discern implications for practice with children using an evaluation rubric of strong, moderate, and weak evidence. The research has implications for assessment of sleep and sleepiness in the schools, for primary and secondary prevention activities, and for interventions by school psychologists targeting children and adolescents with sleep problems that affect their school functioning.