This special issue, Prevention of Aggression, Violence, and Mental Health Problems in Childhood and Adolescence: Innovative and Sustainable Approaches from Around the World, represents a broad set of studies from lower- and middle-income countries. The intent of the special issue was to expand our knowledge of evidence-based programs in less-resourced settings, given that most of the current evidence comes from the USA and other higher-income countries. Many of the articles describe adaptations of evidence-based programs developed in higher-income countries, and their findings suggest that this can be an effective approach. Other studies present evidence for context-specific programs that match cultural norms, are efficient and cost-effective to implement, and are aligned with infrastructure and available resources. We also include articles that provide evidence for the preventive effects of everyday activities such as orchestra participation and after-school programs. Our hope is that the studies reported in this special issue will provide useful guidance for policy makers, funders, and key leaders looking for innovative, affordable, and sustainable solutions to preventing violence in childhood and adolescence and promoting mental health and adjustment around the world.