This chapter explores context of the Sustainable Development Goals (SDGs) and mental health in three distinct South Asian nations: Afghanistan, Bhutan, and the Maldives. Within this comprehensive framework of the 2030 Agenda for Sustainable Development, mental health transcends its classification as a sole health concern (SDG 3) to emerge as a cross-cutting enabler and intrinsic outcome measure across multiple development goals. Afghanistan, ravaged by conflict and humanitarian crises, exemplifies how instability profoundly undermines both mental health and SDG attainment. In stark contrast, Bhutan’s Gross National Happiness (GNH) philosophy explicitly integrates psychological well-being into national policy, though it faces rising challenges like youth unemployment (22.6% in 2020) and associated mental health issues. The Maldives confronts existential climate threats, which exert significant mental health burdens on its population due to displacement fears and economic vulnerabilities. Challenges in integrating mental health into SDG frameworks persist, from governance breakdowns in Afghanistan to operationalization in Bhutan and in the Maldives. Ultimately, achieving truly sustainable development in these nations, addressing the shortages and skill-gaps making mental health a cross-cutting priority will foster a holistic, integrated approach, and recognize that investment in mental health is an indispensable investment in human potential and planetary prosperity.