Large-scale emigration from Korea began around 1904 and continued until the end of World War II. During the Japanese colonial occupation, many Koreans emigrated to Manchuria (present-day China's northeastern provinces of Liaoning, Jilin, and Heilongjiang), other parts of China, the Soviet Union, Hawaii, and the continental United States. Most emigrated for economic reasons employment opportunities were scarce, and many Korean farmers lost their land after the Japanese introduced a system of land registration and private land tenure, imposed higher land taxes, and promoted the growth of an absentee landlord class charging exorbitant rents. Koreans from the northern provinces of Korea went mainly to Manchuria, China, and Siberia. Many people from the southern provinces went to Japan. Koreans were conscripted into Japanese labor battalions or the Japanese army, especially during World War II. In the 1940-44 period, nearly 2 million Koreans lived in Japan, 1.4 million in Manchuria, 600,000 in Siberia, and 130,000 in China. An estimated 40,000 Koreans were scattered among other countries. At the end of World War II, approximately 2 million Koreans were repatriated from Japan and Manchuria.

More than 4 million ethnic Koreans lived outside the peninsula during the early 1980s. The largest group, about 1.7 million people, lived in China. Most had assumed Chinese citizenship. The Soviet Union had about 430,000 ethnic Koreans. One observer noted that Koreans had been so successful in running collective farms in Soviet Central Asia that being Korean was often associated by other Soviets with being rich.

By contrast, many of Japan's approximately 700,000 Koreans had below-average standards of living. This situation occurred partly because of discrimination by the Japanese majority and partly because of the fact that a large number of resident Koreans, loyal to the North Korean regime of Kim Il Sung, preferred to remain separate from and hostile to the Japanese mainstream. The pro-North Korea Chosen soren (General Association of Korean Residents in Japan) initially was more successful than the pro-South Korea Mindan (Association for Korean Residents in Japan) in attracting adherents among residents in Japan. Since diplomatic relations were established between Seoul and Tokyo in 1965, however, the South Korean government has taken an active role in promoting the interests of their residents in Japan in negotiations with the Japanese government (see Relations with Japan , ch. 4). It also has provided subsidies to Korean schools in Japan and other community activities.

By the end of 1988 there were over 2 million South Korean overseas residents. North America was the preferred destination, as the choice of over 1.2 million. Korean immigrants in the United States and Canada gained a reputation for hard work and economic success. South Koreans also were overseas residents of Japan (at least 680,000), Central America and South America (85,000), the Middle East (62,000), Western Europe (40,000), other Asian countries (27353 27,000), and Africa (25,000). A limited number of South Korean government-sponsored migrants settled in Chile, Argentina, and other Latin American countries. Because of South Korea's rapid economic expansion, an increasing number of its citizens reside abroad on a temporary basis as business executives, technical personnel, foreign students, and construction workers. A small number of overseas South Koreans had migrated back to South Korea primarily because of the much improved economic conditions and the difficulties in adjusting to living abroad.

Data as of June 1990