Most Populated Subdivisions in the World

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When talking about population, we frequently focus on nations, but what happens if we go even closer—to the states, provinces, and regions that comprise these nations? A more thorough picture of the dynamics of the world’s population can be seen through these smaller units, also referred to as first-level administrative subdivisions.

Some are home to tens or even hundreds of millions of people, while others are seeing explosive growth that could reshape entire nations. In this post, we explore which subdivisions hold the largest populations, where rapid growth is happening, and why it’s all happening now.

The World’s Most Populated Subdivisions

Let’s begin with the regions that have the highest population totals. These are not just large by area—they’re dense with people, urban centers, and economic activity.

• Uttar Pradesh, India is the global leader, with more than 241 million people—more than any country in the world except for China and India itself.
• The second most populous place in the world, with about 125 million residents, is Maharashtra, India. It is home to Mumbai and Pune. This state is also the second largest economy in India, contributing about 15 percent to the national GDP. Maharashtra attracts migrants from rural areas seeking better job opportunities in the urban centers of this state.
• With more than 127 million people, Guangdong Province, China, has grown through industrialization into a global export powerhouse.
• In the Americas, São Paulo State, Brazil holds around 46 million people. It houses Brazil’s largest city and economic capital.
• California, USA, often seen as a world economy in itself, has a population of nearly 39 million.

These subdivisions are massive not only because of their geography and high birth rates, but also because of their role in national development. Many serve as economic centers or contain megacities, universities, ports, and job markets that draw internal migrants year after year.

Subdivisions with the Fastest Population Growth

While the largest regions are impressive, it’s equally important to look at those growing at the fastest pace. This is where the future of population growth is happening—and where infrastructure is under pressure to keep up.

• Lagos State, Nigeria, is one of the fastest-growing urban regions globally. The city of Lagos could top 80 million people by 2100.
• Dar es Salaam Region, Tanzania, is experiencing rapid urbanization, turning it into a national hub for trade and industry (UN-Habitat).
• Gauteng Province, South Africa, which includes Johannesburg and Pretoria, continues to grow because people move there from other parts of the country. It stands as the province with the most people in South Africa.
• Punjab, Pakistan home to over 127 million people, keeps growing due to high birth rates and cities like Lahore and Faisalabad getting bigger.
• Central Equatoria, South Sudan, has seen a big increase in people since the country became independent. This happens because people are coming back and having children even though the area faces many problems.

Many things affect how fast these areas grow: lots of young people, people moving from the countryside to cities because they offer many jobs, while others grow simply because there are many young people starting families.

If you’re also interested in which subdivisions are the biggest by area, not population, check out my related post: The World’s Largest Subdivisions by Area.