The largest cities in South Korea by population are Seoul (about 9.7 million), Busan (3.4 million), Incheon (3.0 million), Daegu (2.4 million), Daejeon (1.5 million), Gwangju (1.5 million), Suwon (1.2 million), Ulsan (1.1 million), Changwon (1.0 million) and Seongnam (0.95 million). Together these ten cities account for a substantial share of South Korea's roughly 52 million residents, reflecting one of the most heavily urbanised societies on Earth.
The Ten Largest South Korean Cities
South Korea's urban hierarchy is dominated by a single megacity, followed by a string of large regional centres clustered mostly in the southeast and along the western coast. The figures below refer to city-proper populations rather than wider metropolitan areas:
- Seoul — about 9.7 million, the capital and undisputed centre of national life.
- Busan — 3.4 million, the country's largest port and second city.
- Incheon — 3.0 million, gateway to Seoul and home to the main international airport.
- Daegu — 2.4 million, an inland industrial and textile hub.
- Daejeon — 1.5 million, a science and research centre.
- Gwangju — 1.5 million, the cultural heart of the southwest.
- Suwon — 1.2 million, a fortress city in Gyeonggi Province.
- Ulsan — 1.1 million, an industrial powerhouse.
- Changwon — 1.0 million, a planned manufacturing city.
- Seongnam — 0.95 million, a satellite city of Seoul.
Seoul and the Capital Region
Seoul towers over every other Korean city. With around 9.7 million people within its boundaries, it is comfortably the most populous, but its true weight comes from the surrounding Seoul Capital Area, which folds in Incheon, Suwon, Seongnam and dozens of other cities in Gyeonggi Province. This single metropolitan region houses close to half of South Korea's entire population, an extraordinary concentration for any developed nation. Seoul is the seat of government, the financial centre, the media capital and the home of major conglomerates such as Samsung, Hyundai and LG. Three of the ten largest cities on this list — Incheon, Suwon and Seongnam — are effectively part of Seoul's commuter belt, linked by one of the world's most extensive subway and rail networks.
Busan and the Southeastern Industrial Belt
Busan, with roughly 3.4 million residents, is the country's second city and a maritime hub of global importance. Its harbour is one of the busiest container ports in the world, handling much of South Korea's seaborne trade. The southeast is also where several other heavyweight cities sit close together. Ulsan, despite a population of about 1.1 million, is the wealthiest city per capita in the country thanks to the world's largest single automobile plant, a giant shipyard and a major petrochemical complex. Nearby Changwon was purpose-built in the 1970s as a planned industrial city and now anchors a cluster of machinery and electronics manufacturers. Daegu, inland to the north, completes the southeastern grouping as a historic centre of textiles and commerce.
Regional Centres: Daejeon, Gwangju and the Rest
Beyond Seoul and the southeast, two cities serve as the main hubs for the central and southwestern parts of the country. Daejeon, with about 1.5 million people, is South Korea's science and technology capital, hosting the Daedeok research cluster, the KAIST university and numerous government research institutes. Gwangju, also around 1.5 million, is the cultural and political heart of the Jeolla region and is widely remembered for the 1980 democratic uprising that became a turning point in the nation's path to democracy. These cities, along with Suwon's well-preserved Hwaseong Fortress, show how Korea's urban map blends ancient history with rapid 20th-century industrial growth.
Why South Korea Is So Urbanised
More than 80 percent of South Koreans live in cities, and that share keeps rising even as the national population begins to plateau. The transformation has been swift: in 1960 the country was largely rural, but decades of export-led industrialisation drew millions to urban centres in search of factory and office work. Mountainous terrain covers about 70 percent of the peninsula, squeezing the population into a relatively small amount of habitable lowland and intensifying urban density. The result is a landscape of compact, high-rise cities served by efficient public transport. If you enjoy testing yourself on capitals and major cities around the globe, try our interactive geography games.
Half the Country Lives Around One City
The Seoul Capital Area, taking in Seoul, Incheon and Gyeonggi Province, holds roughly half of South Korea's entire population on about twelve per cent of its land. It is among the most concentrated national populations anywhere.
The concentration is recent and deliberate in origin. Postwar industrial policy directed investment towards the capital region, the chaebol conglomerates built their headquarters there, and the best universities are clustered in Seoul, which pulls each successive generation of students who then stay.
Successive governments have tried to reverse it. Sejong City was built from 2007 specifically to take government ministries out of Seoul, and most have moved, though the presidential office and the National Assembly remain in the capital.
Seoul Was Rebuilt From Almost Nothing
The Korean War passed through Seoul four times between 1950 and 1953, and the city changed hands repeatedly. By the armistice much of it was destroyed and the country's per capita income was comparable to the poorest in Africa.
The growth that followed, often called the Miracle on the Han, took South Korea from that position to a member of the OECD within four decades. The Han River, which runs through the capital, gave the phrase its name and is now lined with parks built on former industrial banks.
The Cheonggyecheon stream, covered over by a road and then an elevated expressway during that boom, was uncovered again between 2003 and 2005 and restored as a public waterway, which became an internationally cited example of removing urban motorway rather than adding it.
The Capital Sits Close to the Border
Seoul is roughly 50 kilometres from the Demilitarized Zone, which means the metropolitan area lies within range of conventional artillery positioned on the northern side. That proximity shapes civil defence, subway design and national politics in ways no other large city faces.
The DMZ itself is about 250 kilometres long and four kilometres wide, and because it has been essentially unentered since 1953 it has become an accidental nature reserve, holding populations of cranes and other species that have been squeezed out elsewhere on the peninsula.
Incheon, the second city of the capital region, was where the 1950 amphibious landing turned the course of the war, and its airport, built on reclaimed land between two islands and opened in 2001, is consistently rated among the best in the world.
Busan Faces the Other Direction
Busan, in the far south-east, is the second-largest city and the country's main port, among the busiest container harbours in the world. During the war it was the temporary capital and the centre of the Pusan Perimeter, the last defensible corner of the peninsula, and its population swelled with refugees who never left.
The Gamcheon Culture Village, a hillside of brightly painted houses that began as a refugee settlement, is now among the most photographed places in the country.
Busan has its own dialect, a substantial film festival, and a rivalry with Seoul that runs through Korean popular culture. It is also closer to Fukuoka in Japan than to the Korean capital.
A Country That Is Running Out of People
South Korea has the lowest fertility rate in the world, falling below 0.8 births per woman, which is less than half the level needed to keep a population stable. The national population began declining in 2020.
The causes debated most often are housing costs in the capital region, the expense of private education, and working hours, and all three are concentrated in exactly the cities on this list.
The effect is already visible outside the capital: rural counties and smaller cities are classed as at risk of disappearance, schools are closing, and the government has offered cash incentives with little measurable effect. Seoul continues to grow by drawing the young from everywhere else, which accelerates the decline in the places they leave. The peninsula that frames all of this is described in our South Korea country guide.
Common Questions About South Korean Cities
What is the largest city in South Korea?
Seoul is by far the largest, with around 9.7 million people inside the city limits. Including its wider metropolitan region, the Seoul Capital Area holds close to 26 million people — almost half the national population.
What is the second largest city in South Korea?
Busan is the second largest, with about 3.4 million residents. It is the country's principal seaport and a major centre for trade, fishing, tourism and film, hosting the internationally renowned Busan International Film Festival.
How many people live in South Korea?
South Korea has a total population of roughly 52 million. Population growth has slowed sharply in recent years due to one of the world's lowest birth rates, though urban concentration in the largest cities continues.
Is Incheon part of Seoul?
Incheon is a separate, self-governing metropolitan city of about 3.0 million people, but it lies within the greater Seoul Capital Area and is closely connected to the capital by subway and expressway. It is best known as the location of Incheon International Airport.
How big is Seoul?
The city proper holds around nine and a half million people, and the wider Seoul Capital Area including Incheon and Gyeonggi is above 25 million, roughly half the national population.