This new report examines the relationship between girls’ sport participation and mental health. The data provides strong evidence that in high quality sport settings, playing sports can help lower depression and anxiety and enhance peer relationships and meaning and purpose. The study helps to identify the aspects of the sport setting that drive these outcomes, including levels of autonomy, coach relationships and more. The report also explores the unique qualities of sport relative to other extracurricular activities as well as the connection between them. Findings from the report are integrated into policy and practice recommendations that demonstrate how they can be applied in the field.