Public mental health deals with mental health promotion, prevention of mental disorders and suicide, reducing mental health inequalities, and governance and organization of mental health service provision. The full impact of mental health is largely unrecognized within the public health sphere, despite the increasing burden of disease attributable to mental and behavioral disorders. Modern public mental health policies aim at improving psychosocial health by addressing determinants of mental health in all public policy areas. Stigmatization of mental disorders is a widespread phenomenon that constitutes a barrier for help‐seeking and for the development of health care services, and is thus a core issue in public mental health actions. Lately, there has been heightened interest in the promotion of positive mental health and wellbeing. Effective programmes have been developed for promoting mental health in everyday settings such as families, schools and workplaces. New evidence indicates that many mental disorders and suicides are preventable by public mental health interventions. Available evidence favours the population approach over high‐risk approaches. Public mental health emphasizes the role of primary care in the provision of mental health services to the population. The convincing evidence base for population‐based mental health interventions asks for actions for putting evidence into practice.