Seoul: population

Seoul, South Korea: 22.5 million people in 2025, by the UN estimate.

Rank among the cities of the country: 1 of 49.

In 1975 it had 10.1 million people.

In 2000 it had 19 million people, so it has grown by 19% since then.

For 2050 the UN projects 21.2 million people.

A city here is a dense area of at least 1,500 people per km² with at least 50,000 people, drawn on a population grid by the UN degree of urbanisation. It can differ from the city’s administrative borders and from national statistics. Years from 2026 on are projections.