The challenge of improving population mental health and reducing mental health inequities is addressed in this chapter. Adopting a comprehensive public health approach reframes this challenge to focus on promoting the mental health potential and well-being of people and the everyday settings in which they live. The importance of positive mental health for well-being and overall development at a population level is outlined. Addressing the social determinants of mental health calls for action across sectors, including a whole-of-government and whole-of-society approach, in creating the conditions that will protect and promote people’s mental health and well-being. An overview of international developments in terms of policy frameworks and practice is given, including the integration of mental health into the global health agenda and the framework of the sustainable development goals.