2015 Megacities

In 2015, the world’s megacities—urban areas with populations exceeding 10 million—were emblematic of rapid global urbanization, particularly in Asia and the Global South. Tokyo, the largest megacity, boasted a population of over 37 million, reflecting Japan’s long history of urban concentration and economic development. Cities like Delhi, Shanghai, Mumbai, and Beijing saw explosive growth due to rural-to-urban migration and economic opportunities, contrasting with older megacities like New York and London, whose growth had stabilized and whose histories date back to colonial and industrial eras. Latin American megacities such as São Paulo and Mexico City also ranked among the largest, shaped by 20th-century industrialization and internal migration. While some megacities, especially in developed countries, were experiencing slower growth or even population decline, those in developing nations were expanding rapidly, often facing challenges related to infrastructure, housing, and social services. The 2015 megacity landscape thus highlighted both the historical trajectories and contemporary demographic trends shaping the world’s largest urban centers.

Data from UN World Urbanization Prospects