Second new report World Urbanization Prospects 2025: Summary of Results of the United Nations, published in November 2025, Jakarta currently leads the 2025 ranking of the most populous cities in the world with 42 million inhabitants, followed by Dhaka (40 million) and Tokyo (33 million).
The report shows the most recent data on the urban population in the world, which amounts to 45% of the world population: 3.7 billion people, a number more than doubled compared to 1950, when only 20% of people lived in urban areas. Accordingly, the number of megacities (in English megacities), that is, large interconnected urban agglomerations with more than 10 million inhabitants, is growing and has quadrupled in recent decades: from 8 megacities in the 1970s to the 33 existing today, which, again according to UN estimates, will rise to 37 by mid-century.
Most of these (about twenty) are located in Asia, the continent which, together with Africa, is experiencing the most explosive demographic increase.
The three most populous cities – or rather the three urban agglomerations – on the planet today are:
- Jakarta, the capital and most important city of Indonesia, located on the northwestern coast of the island of Java, which, with its metropolitan area, has almost 42 million inhabitants (more than 70% of the Italian population);
- Dhaka, the capital of Bangladesh, which stands along the banks of the Buriganga river and has almost 40 million people in the entire agglomeration. The city is also at the top of the rankings among the most crowded places on the entire planet with an average density of 45,196 inhabitants/km²;
- Tokyo, the capital of Japan, located on the country’s largest island, Honshū. It is considered the megalopolis par excellence, although it is no longer the most populous, and has 33 million inhabitants.
Despite the rapid global development of megacities, according to the United Nations, much of the growth will take place within medium- and small-sized urban centers: the total number of cities in the world more than doubled between 1975 and 2025, and, according to projections, there could be more than 15,000 cities by 2050. 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.
