Good mental health is a vital part of people’s well-being. This report uses the OECD Well-being Framework to systematically review how people’s economic, social, relational, civic and environmental experiences shape and are, in turn, shaped by their mental health. Based on this evidence, examples of co-benefits, or policy interventions that can jointly improve both mental health and other well-being outcomes, are identified for a range of government departments. Implementing and sustaining such co-benefits requires resources, incentives and working arrangements that enable all relevant stakeholders to contribute to tackling the upstream determinants of mental health. Selected mental health initiatives across OECD countries are reviewed to illustrate how policy makers have been realigning action across government agencies; redesigning policy formulation to address the joint factors influencing mental health; refocusing efforts towards the promotion of positive mental health; and reconnecting with societal stakeholders beyond government, including those with lived experience, youth, civil society and research institutions. How to Make Societies Thrive? Coordinating Approaches to Promote Well-being and Mental Health is the second of two reports as part of a broader OECD project on mental health and well-being.