Accurate, consistent and timely data on population ageing are critical for setting policy priorities to promote the well-being of the growing number of older persons. This is particularly important in the framework of the 2030 Agenda for Sustainable Development, which pledges to leave no one behind. This publication presents the highlights of World Population Ageing 2019, which draws on the latest population estimates and projections published in World Population Prospects 2019. This Highlights report provides an overview of key global and regional trends and dynamics of population ageing and discusses different measures of ageing that include conventional measures as well as prospective and economic measures. A set of Annex tables provides global, regional and national data for selected indicators discussed in the report.