There is a consensus among educators, parents, and policymakers that education should include a focus on supporting essential social and emotional capacities to help children navigate the world successfully. To develop these competencies, many schools adopt social and emotional learning programs. This report reviews the findings from 12 meta-analyses on school-based SEL programs. Across these studies, there is a consistent, reliable effect of tested, evidence-based SEL programs on students’ social, emotional, behavioral, and academic outcomes in PreK–12th grade, including the development of social and emotional skills, improved academic engagement and performance, growth of positive social behaviors, and lower rates of behavior problems and psychological distress. These findings are applicable across gender, ethnicity and race, income, and other demographic variables.