Tourism has become one of the most visible expressions of globalization, combining opportunities for growth with environmental, social, and cultural tensions. The United Nations (UN) has acknowledged this dual role by incorporating tourism into the 2030 Agenda for Sustainable Development, emphasizing its potential to generate employment, foster inclusion, and support environmental protection. Yet international tourism also creates major challenges, from overtourism and ecological degradation to vulnerability to crises and persistent inequalities. This chapter analyzes the UN’s proposals for addressing these issues, with particular attention to the role of the World Tourism Organization (UNWTO) and inter-agency cooperation. Key initiatives include embedding tourism within the SDGs, developing the Measuring the Sustainability of Tourism (MST) framework, establishing principles for sustainable investment, and promoting climate and biodiversity partnerships. The designation of 2017 and 2027 as International Years dedicated to sustainable tourism further underscores the UN’s commitment to positioning the sector within global governance. While these initiatives provide a valuable framework and represent growing international awareness and progress in global governance, their voluntary character, uneven implementation, and insufficient attention to structural inequalities raise doubts about their transformative capacity.