South Korean nationality law

The traditional Joseon kingdom (and later the Korean Empire) did not have codified nationality legislation.[1] After annexation by the Empire of Japan, all Koreans became Japanese subjects. Colonial authorities did not explicitly extend Japanese nationality law to the Korean Peninsula, preventing Korean subjects from automatically losing Japanese nationality by naturalizing as foreign citizens elsewhere.[2]

Korea continued to lack formal regulations until 1948, when the United States Army Military Government in Korea enacted transitionary measures dealing with nationality as it prepared to establish a South Korean state.[3][1] Under these measures, a Korean national was defined as any person born to a Korean father. Children born to a Korean mother only inherited her nationality if the father was stateless or had unknown nationality status. Koreans who had acquired a different nationality were considered to have lost Korean nationality, but could have it restored upon renunciation of that foreign nationality or their removal from the Japanese koseki. The first native law regulating nationality was passed by the Constituent National Assembly later that year and largely carried over this framework.[2]

The 1948 law placed particular significance on the nationality of male heads of household. Foreign women who married Korean men automatically acquired ROK citizenship but the reverse was not true. When foreign men naturalized as South Koreans, their wives and children were concurrently granted citizenship. Foreign women were also unable to naturalize independently of their husbands. Additionally, all naturalized citizens were prohibited from holding high political or military office.[4] These restrictions on public service were repealed in 1963 and major reforms in 1998 decoupled a woman's nationality from that of her husband.[5]

Individuals automatically receive South Korean nationality at birth if at least one parent is a South Korean national, whether they are born within the Republic of Korea or overseas.[6]

Foreign permanent residents over the age of 20 may naturalize as ROK citizens after residing in South Korea for more than five years and demonstrating proficiency in the Korean language.[7] The residency requirement is reduced to three years for individuals with a South Korean parent who were not already ROK citizens,[8] and two years for applicants with South Korean spouses. This is further reduced to one year for applicants who have been married to South Koreans for more than three years.[9] Minor children cannot naturalize independently, but may apply with a foreigner parent who is also naturalizing.[10] Successful naturalization applicants are typically required to renounce their previous nationalities within one year, unless they naturalized through marriage. Individuals who are granted nationality by the Ministry of Justice specifically for their exceptional occupational ability or contributions made to the country are also exempt from this requirement. Exempt individuals must alternatively make a declaration not to exercise their foreign nationality within South Korea.[11]

Naturalization was exceptionally rare until 2000; the average number of foreigners acquiring citizenship from 1948 until that point was 34 people per year. Since then, this rate has sharply increased. The cumulative number of naturalized citizens reached 100,000 in 2011[12] and 200,000 in 2019.[13]

Before 1998, ROK nationality was transferrable by descent to children of South Korean fathers (but not mothers). Individuals who can only trace their South Korean ancestry through the maternal line before this year are not ROK citizens at birth.[14] Persons born to South Korean mothers and foreign national fathers between 13 June 1978 and 13 June 1998 were able to apply for South Korean nationality without any residency requirements until 31 December 2004.[15]

South Koreans residing abroad who voluntarily acquire a foreign nationality automatically have their ROK citizenship revoked[16] and are obligated to report this change of status to the Ministry of Justice.[17] ROK nationals may also lose South Korean nationality when they obtain foreign national status indirectly or involuntarily through marriage, adoption, or legal recognition of parentage. These individuals have a six-month period to make a formal declaration of their intention to retain South Korean nationality.[18]

ROK nationality can also be relinquished by application to the Ministry of Justice.[19] Female citizens who are also foreign nationals at birth must declare their intention to retain or renounce ROK nationality before age 22.[20] Male citizens who obtained foreign nationality by birth must make this declaration before 31 March of the year they become age 18. Dual nationals who retain South Korean nationality after this point are subject to conscription orders[21] and are not permitted to renounce ROK nationality until they have completed military service.[22]

Former South Korean nationals may subsequently apply for nationality restoration, subject to the renunciation of their previous nationalities.[23] However, former nationals who reacquire ROK nationality after reaching age 65 with the intention of permanently residing in South Korea are exempt from this requirement.[24]

South Korean nationals are required to register for South Korean identity cards,[25] eligible to hold Republic of Korea passports,[26] and able to vote in all elections on the national and local level.[27] Dual citizens are prohibited from holding any office that requires them to perform official duties of state.[28] All male citizens[29] between the ages of 18[30] and 35[31] are required to perform at least two years of military service.[32] When travelling to foreign destinations, South Koreans may enter 189 countries and territories without a visa, as of 2020.[33]