More than 12 million people live in Jakarta in 2026, making it the most populous city in Southeast Asia based on administrative boundaries. But Jakarta is not the only city in the region that has grown into an urban center with millions of residents.
From Vietnam to Myanmar, Thailand, Singapore, and Indonesia, Southeast Asia’s major cities are home to large and growing populations. Interestingly, the ranking can look different when a city is measured beyond its administrative boundaries.
The Most Populous Cities in Southeast Asia
According to the World Population Review 2026, Jakarta ranks first with 12,545,537 residents. Ho Chi Minh City comes second with 10,545,905, followed by Hanoi with 9,406,046.
Four other Indonesian cities also make the list, alongside Bangkok, Yangon, and Singapore. Here are the 10 most populous cities in Southeast Asia in 2026:
- Jakarta, Indonesia: 12,545,537
- Ho Chi Minh City, Vietnam: 10,545,905
- Hanoi, Vietnam: 9,406,046
- Bangkok, Thailand: 5,186,582
- Yangon, Myanmar: 4,556,371
- Singapore: 4,247,430
- Bekasi, Indonesia: 4,221,996
- Depok, Indonesia: 3,869,259
- Tangerang, Indonesia: 3,571,253
- Surabaya, Indonesia: 3,321,922
These figures are based on the population within each city’s administrative boundaries. In other words, they show how many people live within a city’s official limits, rather than the entire urban area that has developed around it.
Jakarta Is Much Bigger Than It Looks
The difference becomes especially clear when we look at Jakarta. The World Population Review counts 12,545,537 residents within Jakarta’s administrative boundaries in 2026. Meanwhile, the UN’s World Urbanization Prospects 2025 puts Jakarta’s urban area at 41.9 million people in 2025.
Why is the gap so large? The UN does not look only at government boundaries. It also considers built-up areas that have physically merged with Jakarta and expanded into surrounding regions.
The UN uses the Degree of Urbanization approach to identify these areas through satellite imagery. The method covers built-up areas with a density of more than 1,500 people per km² that are physically connected and have at least 50,000 residents.
This means an urban area can extend beyond the administrative limits of the city it is associated with. The same approach helps explain Manila’s different figures: it has 1,909,418 residents within its administrative boundaries, but its urban area reached 24.7 million people in 2025.
Southeast Asia’s Cities Will Keep Growing
The distinction between administrative cities and wider urban areas becomes even more relevant when looking toward 2050. The UN projects that the number of megacities with at least 10 million residents will rise from 33 in 2025 to 37 by 2050.
Jakarta’s urban area is projected to reach 51.8 million people by 2050, while Manila is expected to reach 27.1 million. Both are projected to keep growing even as global population growth slows overall.
Kuala Lumpur is also projected to surpass 10 million residents, joining Jakarta and Manila as Southeast Asian megacities under the broader urban-area definition.
As cities continue to grow, understanding their size requires more than looking at the numbers within administrative boundaries. Urban areas are expanding, becoming increasingly connected, and in many cases stretching far beyond the official limits of a city.
