In 2022, the World Health Organization (WHO) estimated that around one in eight people globally were living with a mental disorder. Positive mental health is vital to individual and public health, and society in general. However, there is growing evidence that anxiety, stress, depression, and other mental disorders are increasing worldwide, exacerbated by an alarming shortage of trained mental health workers and integrated mental health services. This paper builds on our 2022 World Government Summit (WGS) report on making wellbeing a national priority, and proposes key measures and initiatives that governments can introduce now to deliver sustained results. Our key recommendations for policymakers focus on three areas where well-designed and adequately funded policies and programs will deliver the maximum return on investment in terms of improving the mental wellbeing of all citizens.