Population ageing is a defining global trend of the time. People are living longer, and more are older than ever before. Spectacular improvements in health and survival and reductions in fertility have driven this momentous shift, which has begun or is expected to begin soon in all countries and areas. This change brings both challenges and opportunities as countries strive to achieve the Sustainable Development Goals (SDGs). In 2022, the world marked the twentieth anniversary of the adoption of the Madrid International Plan of Action on Ageing. To commemorate this landmark, the World Social Report 2023 explores the economic and social implications of the ageing of the human population. It builds on the Plan of Action’s framework for national policies to create equitable, inclusive societies for people of all ages, providing recommendations to put the rights and well-being of older persons at the centre, across the life course.