Background: Sleep problems are common among adolescents and have a negative impact on functioning. A better understanding of factors that contribute to sleep problems in adolescence can help guide more effective, targeted interventions. Objective: The current study examined the associations between reactive and proactive functions of aggression and sleep problems. It was hypothesized that reactive aggression, but not proactive aggression, would be associated with sleep problems and that this relation would be partially accounted for by anxiety symptoms. Methods: Hypotheses were evaluated in a sample of Latino high school students (N = 144, 54% male; mean age = 16.25 years). Results As anticipated, multiple regression analyses provided support for a unique association between reactive, but not proactive, aggression and sleep problems. Further, anxiety symptoms mediated the link between reactive aggression and sleep problems. Conclusions: Results suggest the need to target reactive, but not proactive, aggression for the prevention of sleep difficulties, and anxiety is indicated as a target of treatment. Findings and their implications for intervention are further reviewed.