Joseph Mahoney, Joseph Durlak, and Roger Weissberg compare results from four large-scale meta-analyses of student outcomes related to participation in universal, school-based social and emotional learning (SEL) programs. Their examination includes 356 research reports with rigorous designs and outcome data at post or follow-up from hundreds of thousands of K-12 students within and outside the U.S. on a range of SEL programs. The reviews indicate that universal school-based SEL programs produce positive benefits for participating students on a range of important behavioral and academic outcomes that are evident immediately following the end of intervention and that persist during various follow-up periods. Therefore, current data indicate that SEL programs are both feasible and effective in a variety of educational contexts in many countries around the world.