A majority of South Koreans are irreligious. Christianity (Protestantism and Catholicism) and Buddhism are the dominant confessions among those who affiliate with a formal religion.
According to the results of the 2025 edition of the Korea Research "Public Opinion in Public Opinion" survey, 51% of South Koreans report having no religion; 31% identify with Christianity (20% with Protestantism and 11% with Catholicism); 16% identify with Buddhism; and 1% identify with other religions.
Buddhism was influential in ancient times, while Christianity influenced large segments of the population in the 18th and 19th centuries. However, the two traditions grew most rapidly in membership in the mid-20th century, as South Korean society underwent profound transformations.Pyong Gap Min, 2014. Since 2000, both Buddhism and Christianity have been declining in adherents. Native shamanic religions (namely, Korean shamanism) remain popular and may account for a large share of the seemingly irreligious. Indeed, according to a 2012 survey, only 15% of the population identified as nonreligious in an atheistic sense.WIN-Gallup International: "Global Index of Religiosity and Atheism 2012" . According to the 2015 census, the prevalence of irreligion among South Koreans is highest among youth—about 64.9% among then-20-year-olds.Kim Han-soo, Shon Jin-seok. 신자 수, 개신교 1위… "종교 없다" 56%. The Chosunilbo, 20/12/2016. Retrieved 02/07/2017.
Korea entered the 20th century with a well-established Christian presence, but most of the population practiced native Korean shamanism. The latter tradition never attained the status of a national religious culture comparable to Chinese folk religion, Vietnamese folk religion, or Japanese Shinto; the weakness of Korean shamanism was one of the reasons Christianity became deeply rooted early on.Ogata, Mamoru Billy (1984). A Comparative Study of Church Growth in Korea and Japan: With Special Application to Japan. Fuller Theological Seminary. p. 32 ff. A large share of the population also took part in Confucian rites and held private ancestor worship ceremonies. Adherence to organised religions and philosophies was largely limited to the ruling elites, which, when coupled with the extensive patronage exerted by the Chinese empire, allowed elites to embrace a particularly strict interpretation of Confucianism (namely, Korean Confucianism). Korean Buddhism, despite having an erstwhile rich tradition, was virtually extinct as a Korean religious institution at the dawn of the 20th century, after 500 years of suppression by the Joseon kingdom.Joon-sik Choi, 2006. p. 15 Christianity had followers in the Korean peninsula as early as the 18th century, when the philosophical school of Seohak supported the religion. With the fall of the Joseon in the last decades of the 19th century, the population largely embraced Christianity, as the monarchy and Korean intellectuals looked to the West as a model for modernizing the country and endorsed the work of Catholic and Protestant missionaries.Grayson, 2002. pp. 155-187 During Japanese colonisation in the first half of the 20th century, the linking of Christianity with Korean nationalism was further reinforced by opposition to the Japanese effort to merge native Korean shamanism with State Shinto.Grayson, 2002. pp. 158-161
With the division of Korea into two states after 1945, the North and the capitalist South, the majority of the Korean Christian population, which had been centered in the northern half of the peninsula,Grayson, 2002. p. 158, p. 162 fled to the nascent South Korea.Grayson, 2002. p. 163 It has been estimated that Christians who migrated to the south numbered more than one million.Lankov, Andrei. The Real North Korea: Life and Politics in the Failed Stalinist Utopia. Oxford University Press, 2014. . p. 9. Throughout the second half of the 20th century, the South Korean state enacted measures to further marginalise indigenous Korean shamanism; the measures further strengthened Christianity and fostered a revival of Buddhism.Kendall, 2010. pp. 4-17 According to scholars, South Korean censuses do not count believers in indigenous Korean shamanism and underestimate the number of adherents of Korean shamanism sects.Baker, 2008. pp. 4-5
Some observers suggest that the significant drop in the number of adherents of religions such as Catholicism and Buddhism between the 2005 and 2015 censuses is due to changes in survey methods. The 2005 census involved a comprehensive analysis of the entire population, using traditional data sheets completed by each family. In contrast, the 2015 census primarily used the internet and surveyed only about 20% of the South Korean population as a sample. Critics argue that this shift disadvantaged rural populations, who tend to be more Buddhist and Catholic and less internet-versed, while benefiting urban Protestant groups with better internet access. Both Buddhist and Catholic communities have criticized the results of the 2015 census.
Demographics religion1950–19621985199520052015num. %num. %num. %num. %num. %Christianity11,390,00013,461,00013,566,000(Protestantism)8,505,0008,446,0009,676,000(Catholicism)2,885,0005,015,0003,890,000Buddhism10,154,00010,588,0007,619,000othernon-religious + The percentage of religious beliefs by region in Korea (2025) Administrative area Protestantism Catholicism Buddhism OtherNo religion Seoul 22% 13% 13% 1%51% Incheon/Gyeonggi 21% 12% 12% 1%53% Daejeon/Sejong/South Chungcheong Province 21% 10% 15% 1%53% Gwangju/Jeolla 25% 11% 11% 2%51% Daegu/North Gyeongsang 17% 10% 23% 1%49% Busan/Ulsan/South Gyeongsang 13% 7% 29% 1%49% Gangwon/Jeju 16% 16% 18% 1%49% Korea National 20% 11% 16% 1%51%
Religious affiliation by age (2025) Age ProtestantismCatholicismBuddhismOther religionsNo affiliation18–2930–3940–4950–5960–69Above 70Other religions include Won Buddhism, Confucianism, Cheondoism, Daesun Jinrihoe, Daejongism, and Jeungsanism.
Religious affiliation by gender (2025) ProtestantismCatholicismBuddhismOther religionsNo affiliationMaleFemaleOther religions include Won Buddhism, Confucianism, Cheondoism, Daesun Jinrihoe, Daejongism, and Jeungsanism.
History
Before 1945
Before the introduction of Buddhism, all Koreans believed in their indigenous religion socially guided by mu (shamans). Buddhism was introduced from the Chinese Former Qin state in 372 to the northern Korean state of Goguryeo and developed into distinctive Korean forms. At that time, the peninsula was divided into three kingdoms: the aforementioned Goguryeo in the north, Baekje in the southwest, and Silla in the southeast. Buddhism reached Silla only in the 5th century, but it was made the state religion only in that kingdom in the year 552.Asia For Educators: Korea, 300 to 600 CE. Columbia University, 2009. Buddhism became much more popular in Silla and even in Baekje (both areas now part of modern South Korea), while in Goguryeo the Korean indigenous religion remained dominant. In the following unified state of Goryeo (918–1392) Buddhism flourished, and even became a political force.Vermeersch, Sem. (2008). The Power of the Buddhas: the Politics of Buddhism during the Koryŏ Dynasty (918-1392). p. 3
The Joseon kingdom (1392–1910), adopted an especially strict version of Neo-Confucianism (i.e. Korean Confucianism) and suppressed and marginalised Korean BuddhismGrayson, 2002. pp. 120-138Tudor, 2012. and Korean shamanism. Buddhist monasteries were destroyed, and their number dropped from several hundreds to a mere thirty-six; Buddhism was eradicated from the life of towns as monks and nuns were prohibited from entering them and were marginalised to the mountains. These restrictions lasted until the 19th century.Grayson, 2002. p. 137
In the late 19th century, the Joseon state was politically and culturally collapsing.Grayson, 2002. p. 155 The intelligentsia was looking for solutions to invigorate and transform the nation. It was in this critical period that they came into contact with Western Christian missionaries who offered a solution to the plight of Koreans. Christian communities had already existed in Joseon since the 17th century; however, it was only by the 1880s that the government allowed a large number of Western missionaries to enter the country.Grayson, 2002. p. 157 Christian missionaries set up schools, hospitals and publishing agencies.Grayson, 2002. pp. 157-158 The royal family supported Christianity.Grayson, 2002. p. 158
As the Japanese tried to impose State Shinto during the absorption of Korea into the Japanese Empire (1910–1945), the already formed link of Christianity with Korean nationalism was strengthened, co-opting within it native Korean shamanism, and Christians refused to take part in Shinto rituals. At the same time, numerous religious movements that since the 19th century had been trying to reform the Korean indigenous religion, notably Cheondoism, flourished.Carl Young. Into the Sunset: Ch'ŏndogyo in North Korea, 1945–1950. On: Journal of Korean Religions, Volume 4, Number 2, October 2013. pp. 51-66 / 10.1353/jkr.2013.0010
1945–2015
With the division of Korea into two states in 1945, the communist north and the anti-communist south, the majority of the Korean Christian population that had been until then in the northern half of the peninsula, fled to South Korea. Christians who resettled in the south were more than one million. Cheondoists, who were concentrated in the north like Christians, remained there after the partition, and South Korea now has no more than few thousands Cheondoists.
The so-called "movement to defeat the worship of gods" promoted by governments of South Korea in the 1970s and 1980s prohibited indigenous cults and wiped out nearly all traditional shrines (sadang 사당/祠堂) of the Confucian kinship religion.Kendall, 2010. p. 10 This was particularly tough under the rule of Park Chung Hee, who was a Buddhist.Joon-sik Choi, 2006. p. 17 This measure, combined with the rapid social changes of the same period, favoured a rapid revival of Buddhism, as it traditionally intermingled with folk religion and allowed a way for these traditional believers to express their folk beliefs in the context of an officially accepted religion. This period also saw the growth of Christian churches in a trend to register as members of organised religions.Baker, 2008. p. 4
The number of Buddhist temples rose from 2,306 in 1962 to 11,561 in 1997, Protestant churches rose from 6,785 in 1962 to 58,046 in 1997, the Catholic Church had 313 churches in 1965 and 1,366 in 2005, Won Buddhism had 131 temples in 1969 and 418 in 1997.Baker, 2008. p. 3 Similarly, Daesun Jinrihoe's temples have grown from 700 in 1983 to 1,600 in 1994.Baker, 2003. p. 5 Statistics from censuses show that the proportion of the South Korean population self-identifying as Buddhist has grown from 2.6% in 1962 to 22.8% in 2005, while the proportion of Christians has grown from 5% in 1962 to 29.2% in 2005. However, both religions have shown a decline between the years 2005 and 2015, with Buddhism sharply declining in influence to 15.5% of the population, and a less significant decline of Christianity to 27.6%.South Korea National Statistical Office's 19th Population and Housing Census (2015): "Religion organisations' statistics". Retrieved 20 December 2016
According to Pew Research Center (2010), about 46% of the population had no religious affiliation, 23% are Buddhist and 29% are Christians. According to 2015 national census, 56.1% are irreligious, Protestantism represents 19.7% of the total population, Korean Buddhism 15.5%, and Catholicism 7.9%. A small percentage of South Koreans (0.8% in total) are members of other religions, including Won Buddhism, Confucianism, Cheondoism, Daesun Jinrihoe, Islam, Daejongism, Jeungsanism and Eastern Orthodox Christianity.
2015–present