As of the end of 2008, South Korea's total population was estimated to be 48,606,787 with a density of 498 people per square kilometer. The population of North Korea was estimated to be 23,298,012.

Korea saw its population grow by an annual rate of 3 percent during the 1960s, but growth slowed to 2 percent over the next decade. In 2008, the rate stood at 0.31 percent and is expected to further decline to 0.02 percent by 2020.

In the 1960s, Korea's population distribution formed a pyramid, with a high birth rate and relatively short life expectancy. However, age-group distribution is now shaped more like a bell because of the low birth rate and extended life expectancy. Those aged 15 and younger will make up a decreasing portion of the total, while senior citizens (65 and older) will account for some 15.7 percent of the total by the year 2020.

The nation's rapid industrialization and urbanization in the 1960s and 1970s has been accompanied by continuing migration of rural residents into the cities, particularly Seoul, resulting in heavily populated metropolitan areas. However, in recent years, an increasing number of Seoulites have begun moving to suburban areas.

The number of foreigners, including short-term sojourners, residing in Korea reached 1,158,866 in 2008. To this end, foreigners now account for two percent of the population. The speed at which Korean society is diversifying in terms of race and culture is evidenced by the 8.7 percent annual growth in the size of the foreign population, which stood at 1,066,273 in 2007.

While 48.9 percent of the foreign population (566,116) was made up of workers, including industrial trainees, another 10.6 percent consisted of individuals who came to Korea through marriage (122,552); meanwhile, 6.2 percent (71,531) were students.

In terms of nationality, Chinese nationals accounted for 57 percent (484,674, 362,920 of which were ethnic Koreans) of the 854,007 long-term foreign residents registered in Korea. The second largest ethnic group was the Vietnamese (79,848, 9.4 percent), followed by Filipinos
(39,372, 4.6 percent), Thais (30,051, 3.5 percent) and Americans (28,853, 3.4 percent). The remainder for the most part hailed from nations such as Indonesia, Taiwan and Mongolia.