The world's largest cities are concentrated disproportionately in Asia, particularly in South Asia, East Asia and Southeast Asia, although major metropolitan populations also occur in Africa, Latin America, North America and elsewhere. The precise answer depends on how a city is defined because a municipal boundary, built up urban area, metropolitan area and urban agglomeration can have very different populations. This is one reason apparently conflicting lists of the world's largest cities can all contain valid numbers. UN DESA's World Urbanization Prospects uses internationally comparable definitions and estimates the populations of major urban areas. Its 2025 revision identifies Jakarta, Dhaka, Tokyo, New Delhi, Shanghai, Guangzhou, Cairo, Manila, Kolkata and Seoul among the ten most populous urban areas in 2025.
Asia's dominance reflects several long term demographic and economic processes. South and East Asia contain enormous national populations, extensive historical settlement networks and many rapidly expanding metropolitan regions. Industrialisation, economic development, migration and natural population increase have contributed to the growth of cities such as Delhi, Dhaka, Jakarta, Shanghai and Manila. Asia also contains many large urban regions that have expanded far beyond their historical cores, creating metropolitan areas with populations distributed across numerous municipalities. The boundaries of these metropolitan systems can be difficult to define, so international datasets use specific methodologies to make comparisons more consistent. The United Nations notes that its 2025 methodology incorporates harmonised spatial approaches alongside national definitions.
Jakarta is particularly important in current global population rankings. According to UN DESA's 2025 World Urbanization Prospects, Jakarta had approximately 41.9 million residents in 2025 under the report's city definition, making it the largest city in the dataset. Dhaka followed with approximately 36.6 million, Tokyo with approximately 33.4 million, New Delhi with approximately 30.2 million and Shanghai with approximately 29.6 million. Guangzhou was estimated at approximately 27.6 million, Cairo at approximately 25.6 million, Manila at approximately 24.7 million, and Kolkata and Seoul at approximately 22.5 million each. These values refer to internationally defined urban populations and should not be confused with the populations of administrative municipalities.
The geographic distribution of megacities is changing. UN DESA defines megacities as urban areas with at least ten million inhabitants and reports that their number increased from eight in 1975 to thirty three in 2025. More than half of these megacities are located in Asia. This reflects the continuing concentration of very large urban populations in countries such as China, India, Indonesia, Bangladesh, the Philippines and Japan. Cairo is notable because it is the only non Asian city in the United Nations 2025 top ten. Other major metropolitan regions in Africa and Latin America remain extremely large even when they do not occupy the first positions in this particular ranking.
Large cities are not distributed solely according to national population size. Economic history, industrialisation, trade, political centrality, geography and transport infrastructure influence urban concentration. Coastal locations have historically supported ports and international trade, while river valleys and fertile plains can support dense settlement. Capitals can become exceptionally large because political institutions, government employment and investment concentrate there. Industrial cities can grow rapidly when factories and associated services attract workers. Modern metropolitan growth is also influenced by global finance, technology, manufacturing, logistics, universities and migration. Consequently, the world's largest cities represent different combinations of demographic, economic and historical processes rather than a single model of urban development.
City rankings are difficult to interpret without understanding boundaries. Tokyo, for example, can refer to the Tokyo Metropolis, the continuous built up urban area, the Greater Tokyo metropolitan region or other statistical units. Similar problems apply to Delhi, Shanghai, Jakarta and other megacities. A municipal population can be substantially smaller than the population of the continuous urban area surrounding it. Conversely, administrative boundaries may encompass rural or sparsely populated territory. The United Nations therefore uses a harmonised methodology intended to improve international comparisons while acknowledging that national definitions remain important. The Degree of Urbanisation approach classifies settlements according to spatial characteristics rather than relying exclusively on administrative boundaries.
The location of large cities is also changing because urban growth is increasingly occurring in Africa and Asia. UN DESA projects that the number of cities worldwide could exceed fifteen thousand by 2050 and expects many of the fastest growing urban populations to be in African and Asian cities. Importantly, very large megacities are only one part of global urbanisation.
The United Nations reports that most of the approximately twelve thousand cities analysed in its 2025 dataset have fewer than one million inhabitants, while eighty one percent have fewer than 250000. Small and medium sized cities therefore account for a substantial part of global urban growth even though megacities attract disproportionate attention.
The world's largest cities are consequently best understood as components of wider urban systems rather than isolated administrative places. They contain dense central districts, suburbs, satellite towns, industrial zones, informal settlements, transport corridors and peri urban areas. Their growth can involve densification in some locations and outward expansion in others. This creates simultaneous processes such as suburbanisation, sprawl, regeneration, reurbanisation and informal settlement growth within the same metropolitan region.
Understanding where the largest cities are therefore requires attention to both population geography and the definitions used to measure cities. The UN World Urbanization Prospects provides a major international reference because it supplies comparable estimates across countries and publishes data covering cities, towns and rural populations.
