Christian Population of South Korea

Background

The principal nationwide source for South Korea's religious population is the Population and Housing Census conducted by Statistics Korea. A question on religion was first included in the 1985 census and was asked again every ten years thereafter, in the 1995, 2005, and 2015 censuses. The questionnaire lists "Christianity (Protestant)" and "Christianity (Catholic)" as separate options. Accordingly, in census statistics, "Christian population" refers to the combined total of Protestants and Catholics, while "Protestant population" refers to Protestants alone.

Because the census counts the religion that respondents report for themselves, its figures may differ from the membership numbers compiled by churches. For example, the number of Catholics in the 2015 census (3.89 million) was far lower than the figure the Catholic Bishops' Conference of Korea announced at the end of the same year (approximately 5.65 million).

Development

• 1985: Religion was surveyed for the first time. From this census through the 2005 census, Buddhists outnumbered Protestants.
• 1995: The Protestant population was counted at approximately 8.76 million.
• 2005: The Protestant population numbered in the mid-8 millions, and 52.9 percent of the total population reported having a religion. The 2005 figures cited for comparison when the 2015 results were released varied slightly among media outlets.
• 2015: With November 1, 2015, as the reference date, 20 percent of households nationwide were selected and surveyed through enumerator interviews and online responses; the results were released in December 2016. Protestantism was the largest religion, with approximately 9,676,000 adherents (19.7 percent), followed by Buddhism with approximately 7,619,000 (15.5 percent) and Catholicism with approximately 3.89 million (7.9 percent).

Results and Impact

In the 2015 census, Protestantism surpassed Buddhism for the first time since the religion question was introduced. The Protestant population grew by more than one million from 2005, while the Buddhist population declined by nearly three million. The combined Christian population of Protestants and Catholics was approximately 13.57 million, more than one quarter of the total population.

In the same census, those reporting no religion accounted for 56.1 percent of the population, exceeding half for the first time. Among people in their twenties, this proportion reached 64.9 percent. The regions with the highest proportions of Protestants were North Jeolla Province (26.9 percent), Seoul (24.2 percent), and South Jeolla Province (23.2 percent). The 2015 results subsequently became the benchmark widely cited in church circles when discussing the church's numerical strength. Ahead of the 2025 census, some church organizations urged their members to answer the religion question accurately.

Assessment

Interpretations of the 2015 results differed among religious communities.

• Buddhist community: The Buddhist community took the position that it could not readily accept the finding that its adherents had declined by nearly three million in ten years. It also pointed out that the census was a sample survey rather than a complete enumeration and raised the possibility that enumerators had been biased toward a particular religion. Statistics Korea responded that it had taken special care to prevent bias during the survey process and that the results were broadly consistent with trends in other social surveys.
• Catholic community: An official of the Catholic Pastoral Institute of Korea stated that the number of Catholics in the 2005 census appeared to have been somewhat inflated and that the 2015 results, in which respondents entered their answers directly, were more accurate.
• Protestant community: The unexpected increase prompted calls for caution. Some church media outlets suggested that "Canaan believers" (professing Christians who do not attend church) and members of groups that various denominations have designated as heretical might have answered "Protestant." NewsNJoy attributed the increase mainly to natural growth from births in Protestant families and argued that the number of adult Protestants had in fact declined. As evidence, it noted that the proportion of Protestants among those aged 10 to 14 (24.2 percent) was higher than the overall average.

Census figures thus serve as the most authoritative data on the size of Korean Christianity. Opinions differ, however, on how those figures relate to actual church attendance and religious practice.