South Korea Population

South Korea is the world's 31st most populous country, home to about 51.6 million people in 2026. Set in Eastern Asia, its demographic path this century turns on the balance of births, deaths and migration. It packs in roughly 522 people per square kilometre.

South Korea's population has already passed its peak of about 51.9 million, reached around 2021. It has begun a slow decline, and the UN projects about 45.4 million by 2050 and 22.0 million by 2100. The 50 million threshold was crossed near 2014.

The median age is set to climb from about 45 today to roughly 60 by 2100, while life expectancy, near 84 years, keeps rising. That ageing slowly changes everything from the size of the workforce to the cost of care and pensions.

At about 0.73 births per woman, South Korea has one of the world's lowest fertility rates, well under the replacement level of around 2.1. Immigration is a meaningful contributor, bringing in more people than leave in a typical year.

These figures follow the UN's medium variant, the most widely cited scenario. The low and high variants, driven mainly by differing fertility assumptions, fan out into a wide range by 2100, so treat each number as a central estimate rather than a precise forecast.