Aggressive and defiant behaviors in students are costly to schools, teachers, and students. In this paper, we summarize findings from meta-analyses, systematic reviews, and meta-reviews that examined school-based interventions for aggressive and defiant behaviors in students. Results of the review suggest that school-based interventions produce significant but small positive effects on aggression and defiance, with larger effects for interventions that are implemented with higher quality. Behavioral and cognitive behavioral techniques are key components of nearly all effective school interventions, whether interventions are student-directed or teacher-/environment-directed. Specific interventions with empirical support, as identified using the Blueprints for Healthy Youth Development and "What Works Clearinghouse" databases, are briefly summarized. Finally, recommendations are made for schools considering a school intervention for aggression and defiance, and important priorities for future research are outlined.