Second new report World Urbanization Prospects 2025: Summary of Results of the United Nations, published November 2025, Jakarta currently leads the 2025 ranking of most populous cities in the world with 42 millions of inhabitants, followed by Dhaka (40 million) e Tokyo (33 million).
The report shows the latest data on the urban population in the world, which amounts to 45% of the world population: there are 3.7 billion people, a number more than doubled compared to 1950, when only the 20% of people lived in urban areas. Accordingly, also the number of megacities (in English megacities), that is, large interconnected urban agglomerations with more than 10 million inhabitants, is growing and is quadrupled in recent decades: from the 8 megacities of the Seventies to the 33 existing today, which, again according to UN estimates, will rise to 37 by mid-century.
Most of these (about twenty) are found in Asiathe continent which, together withAfricais experiencing the most explosive population growth.
The three most populous cities – or rather the three urban agglomerations – on the planet today are:
- Jakartathe capital and most important city ofIndonesialocated on the northwestern coast of the island of Java, which, with its metropolitan area, almost counts 42 million inhabitants (more than 70% of the Italian population);
- Dhakacapital of Bangladeshwhich rises along the banks of the Buriganga River and counts almost 40 million of people in the entire agglomeration. The city is also at the top of the charts among the most crowded places on the entire planet with an average density of 45 196 inhabitants/km²;
- Tokyothe capital of Japanlocated on the country’s largest island, Honshū. It is considered the megalopolis par excellence, although it is no longer the most populous, and it counts 33 million inhabitants.
Despite the rapid global development of megacities, much of the growth will occur within urban centers, according to the United Nations medium and small dimensions: the total number of cities in the world more than doubled between 1975 and 2025, and, according to projections, by 2050 there could be more than 15,000 cities. It is estimated that in that same year two thirds of the growth of the entire human race will now take place within urban centers.
