We describe the results of a systematic review of the literature on children’s mental health using a public health model consisting of three levels of mental health service: universal, targeted, and intensive. At the universal level, strong evidence exists for the effectiveness of occupation- and activity-based interventions in many areas, including programs that focus on social–emotional learning; schoolwide bullying prevention; and after-school, performing arts, and stress management activities. At the targeted level, strong evidence indicates that social and life skills programs are effective for children who are aggressive, have been rejected, and are teenage mothers. The evidence also is strong that children with intellectual impairments, developmental delays, and learning disabilities benefit from social skills programming and play, leisure, and recreational activities. Additionally, evidence of the effectiveness of social skills programs is strong for children requiring services at the intensive level (e.g., those with autism spectrum disorder, diagnosed mental illness, serious behavior disorders) to improve social behavior and self-management.