This review examines the history and contemporary landscape of school mental health, describing evidence that schools are an essential component of the system of child and adolescent care and providing recommendations to advance this vital care delivery system. This literature review of scientific data and shifts to policy and practice in school mental health documents the evolution of collaboration between the education and mental health systems to support student mental health. This review describes best practices and provides examples for achieving the standards of the comprehensive school mental health systems model in states and local communities. Data demonstrate thatmultitiered systems ofmental health support and services in schools, including mental health promotion, prevention, early intervention, and treatment, improve academic and psychosocial functioning and reduce risk of poor outcomes, including mental illness and school failure. Policy and practice shifts in the field reflect a movement toward integrating mental health systems into the education sector, including preparing the education workforce to promote mental health and to support early identification of and intervention to address mental illness. To create a full continuumofmental health supports for students, states and districts can draw on national best practices and state exemplars as they install multitiered systems of mental health supports in all schools, conduct universal student mental health monitoring, and coordinate school and community mental health systems.