Most Populous Cities

Data

Source: Wikipedia — List of largest cities.

Note: What You Should Know About the World's Most Populous Cities

What does "most populous city" actually mean?

It sounds like a simple question, but there's no single answer — and the numbers can shift wildly depending on how you draw the line. When people say a city is "most populous," they usually mean one of two very different measurements:

• City proper counts only the people living inside the official municipal boundary. It's a legal, administrative definition. For example, the city proper of Shanghai has a much smaller population than the whole metro area that surrounds it.
• Metropolitan area (or agglomeration) counts everyone in the continuously built-up urban region, including the suburbs, satellite towns, and neighboring districts that are economically tied to the core. This is the more realistic number, and it's what this page shows.

The metro figure is usually far bigger — often two to three times the city-proper total — because suburbs are where much of modern urban living takes place.

The giants dominate from Asia

Look down the table and one pattern jumps out: six of the top ten cities are in Asia. Rapid industrialization, rural-to-urban migration, and enormous national populations have supercharged Asian megacities over the past few decades.

• Tokyo tops the list with about 37.4 million people and has held the #1 spot for decades — the world's largest metropolitan area.
• Delhi is growing fast and routinely battles Tokyo for first place in different datasets.
• Shanghai and Beijing anchor China's economic powerhouse, each supporting well over 20 million residents.
• Dhaka and Mumbai are among the most densely packed megacities on Earth.

Outside Asia, Sao Paulo (Brazil), Cairo (Egypt), and Mexico City (Mexico) carry the global south's heavyweights — each a mega-region in its own right.

Megacities, urbanization, and what's next

A "megacity" is usually defined as an urban area home to 10 million or more people. By that measure, every city in this table qualifies. Humanity is now majority-urban, and the share keeps rising, which means megacities are multiplying — particularly across Asia and Africa.

• More than half the world's people already live in cities, and the UN projects the share will keep climbing for decades.
• A century ago, almost no city had 10 million residents. Today dozens do, and the number grows each year.
• Megacity populations can be a moving target: borders redraw, census methods change, and estimates between agencies can differ by millions.

Tips for reading this data

• Always check whether a figure is "city proper" or "metro area" before comparing two lists — mixing them is the most common mistake.
• These rankings shift over time, so mind the year of the estimate.
• Records aren't perfectly comparable across countries, so treat small rank differences with a pinch of salt.

Fun facts

• Tokyo's metro area is roughly triple the entire population of Australia.
• If Delhi keeps growing at its pace, many projections put it ahead of Tokyo within a decade or two.
• Together, the ten cities in this table hold more people than the United States.
• Mexico City is slowly sinking — some areas have dropped more than 10 meters over the last century.
• Sao Paulo's metro is larger than the populations of more than 100 individual countries.
• "Megacity" was coined back in the 1960s, when a 10-million-person city seemed almost unimaginable.

Figures follow the urban agglomeration definitions used on this page and are educational estimates; exact numbers vary slightly by source.