This report presents the findings of a systematic literature review of programs and services implemented in childhood and adolescence that aim to prevent anxiety and depression disorders and symptoms. The review identified a range of high-quality systematic reviews which demonstrate that prevention interventions have small but significant effects in reducing anxiety, depression, and internalising symptoms and disorders in children and adolescents. While many of the included interventions addressed only one or two risk or protective factors that affect child mental health, multiple factors may need to be addressed to achieve sustained prevention effects.