This technical brief provides an updated global assessment of mountain population trends from 2000 to 2030, using the UNEP–WCMC mountain classification. The global mountain population is projected to reach 1.19 billion by 2030, with Africa showing the fastest growth and urban areas driving the most significant increases. These dynamics call for inclusive territorial planning, investment in climate-resilient infrastructure and stronger data systems to advance sustainable mountain development and support the Five Years of Action for the Development of Mountain Regions (2023–2027).