The proportion of people with migrant backgrounds living in South Korea rose to 5.4 per cent of the total population in 2025, according to data released on Monday by the South Korean Ministry of Data and Statistics. The migrant-background population reached 2.81 million, up from 2.71 million the previous year, against a national total population of 51.82 million.

How the Migrant Population Is Defined

The ministry classifies people with a migrant background as those who are immigrants themselves or have at least one parent born overseas. The category encompasses foreign nationals, naturalised South Koreans, and second-generation immigrants.

Foreign nationals made up the largest share at 75.1 per cent of the migrant-background population. Second-generation immigrants accounted for 14.1 per cent, while 9.1 per cent had acquired South Korean citizenship through naturalisation or legal recognition of parentage — a process covering children born out of wedlock who are subsequently acknowledged by a parent.

Age and Gender Breakdown

By age, people in their 30s formed the largest cohort at 23.7 per cent (667,000), followed by those in their 20s at 21.6 per cent (607,000). People in their 40s numbered 439,000, or 15.6 per cent of the total. Notably, the 20s age group recorded the largest year-on-year increase, adding 36,000 people over the period.

Younger residents — those aged 24 and under — with a migrant background numbered 790,000, a rise of 6.6 per cent from a year earlier, pointing to a generational deepening of South Korea's demographic diversity. The working-age population (ages 15 to 64) with a migrant background stood at 2.3 million.

By gender, males accounted for 52.5 per cent and females for 47.5 per cent, with a ratio of 110.7 males per 100 females — a skew driven in large part by labour migration patterns.

Geographic Concentration

More than half — 56 per cent — of South Korea's migrant-background residents lived in the greater Seoul metropolitan area, with 17.1 per cent residing in Seoul itself, where they made up 5.1 per cent of the capital's population.

South Chungcheong Province recorded the highest share of migrant-background residents at 8.3 per cent, ahead of both North Chungcheong Province and Gyeonggi Province, each at 6.5 per cent. The southeastern city of Daegu had the lowest proportion at 2.9 per cent, reflecting regional variation in industrial and agricultural employment demand.

Parental Nationalities

Among second-generation immigrants, those with Vietnamese parents formed the largest group at 28.1 per cent, followed by those with Chinese parents at 15.7 per cent. Ethnic Koreans of Chinese nationality accounted for a separate 11.4 per cent. Other significant source countries included Uzbekistan, the Philippines, Cambodia, Mongolia, and Nepal — a mix that reflects South Korea's bilateral labour agreements and marriage migration patterns across Southeast and Central Asia.

Broader Demographic Context

South Korea has one of the world's lowest birth rates, and the steady rise of its migrant-background population is increasingly being tracked as a partial offset to acute demographic shrinkage. This is the second consecutive year in which the migrant-background share of the population has registered a measurable increase. As policy debates around immigration reform intensify in Seoul, the data will likely inform upcoming legislative discussions on labour, welfare, and integration spending.