This article introduces the new journal Advances in School Mental Health Promotion. Following definitions of key concepts, critical themes associated with high-quality school mental health promotion are reviewed. Reasons for the growth of the field, along with evidence of progress in a number of developed nations, are presented. We then discuss challenges being encountered, including those related to high variability in experience across communities, states and nations, stigma and marginalization, funding and resource limitations, language barriers, the limited focus on school-wide promotion, universal prevention, social and emotional learning and climate, a significant research to practice gap, training and workforce concerns, and issues around youth, family and other stakeholder involvement. Each of these areas includes critical opportunities for the advancement of training, practice, research and policy, building interconnections between these realms, and development of collaborative research agendas within and across countries. We conclude with a review of global initiatives and opportunities related to school mental health promotion and briefly describe the articles in this inaugural issue.