This article describes what is known about mental health in children, adolescents, adults, and the elderly globally in high-, middle- and low-income countries. The social determinants of health are described as well as the paradigm shift from focusing on psychopathology to looking at ways in which individuals and communities can embrace mental health promotion to decrease stigma and provide care for all individuals in resource-rich and resource-poor environments. The need to expand the content in nursing curricula to include mental health concepts at all levels of training, foster mental health research, and promote international collaboration around best practices is also discussed.