Thailand is overwhelmingly Theravada Buddhist: the National Statistical Office’s 2018 pilot census counted 93.46% of residents as Buddhist, 5.37% as Muslim and 1.13% as Christian, with Hindus and Sikhs together under 0.02%. The constitution names no state religion but commits the state to promoting Buddhism while guaranteeing religious freedom, and Thai law formally recognises five religions: Buddhism, Islam, Christianity, Hinduism and Sikhism. Muslims are concentrated in the far south, Christians in the northern hills, and Hindu, Sikh and Chinese temples in Bangkok and the trading towns. Surveys outside the census give somewhat different shares (Ipsos put Buddhists at about 90% and Christians at 4% in 2023; Pew estimated Muslims at 7% the same year), so each community is best understood through its own history and places of worship.
Theravada Buddhism: 93.46% of Thais, from Sukhothai to Wat Phra Kaew
Buddhist missionaries may have reached the region as early as the reign of the Indian emperor Ashoka in the 3rd century BCE, and the Mon kingdom of Dvaravati (roughly the 6th to 11th centuries) left Dharma wheels, Buddha footprints and Pali inscriptions at sites such as Nakhon Pathom. Khmer and Srivijayan rulers brought Mahayana Buddhism and Hindu Brahmanism to other parts of the country. The decisive turn came in the 13th century, when Thai monks travelled to Sri Lanka to be ordained in the Mahavihara Theravada lineage. King Ram Khamhaeng of Sukhothai, the first Thai kingdom (founded in 1238), invited these Lankavong monks from Nakhon Si Thammarat to his capital, built monasteries for them and created the office of sangharaja, head of the monastic community. In the northern kingdom of Lan Na, King Mangrai built Wat Chiang Man in Chiang Mai around 1297, and King Tilokaraj (r. 1441–1487) enlarged Wat Chedi Luang to house the Emerald Buddha and hosted a council around 1477 to review the Pali Canon, counted as the eighth Buddhist council in the Thai tradition.
Every later dynasty patronised the sangha. In Ayutthaya, King Borommatrailokkanat (1431–1488) himself spent eight months as a monk, and King Boromakot (r. 1733–1758) sent 25 monks to Sri Lanka to restore higher ordination there, founding the Siam Nikaya that still exists on the island. Rama I (r. 1782–1809), founder of the Chakri dynasty and of the new capital at Bangkok, appointed the first Supreme Patriarch of Thai Buddhism and began Wat Phra Kaew in 1783 inside the Grand Palace. The temple houses the Emerald Buddha, a 66-centimetre jasper or jade image regarded as the kingdom’s palladium, and it remains the setting for state ceremonies presided over by the king.
King Mongkut (r. 1851–1868), who had spent 27 years as a monk, founded the stricter Dhammayuttika order while still in robes. Thai Buddhism is now divided into that royally backed order and the much larger Maha Nikaya, both overseen by the Supreme Patriarch and the Sangha Supreme Council. Since a December 2016 amendment to the Sangha Act, the king appoints the Supreme Patriarch directly, with the prime minister countersigning; the current holder, Ariyavongsagatanana IX, has served since 12 February 2017. Thai Buddhism is known for short-term ordination, in which young men traditionally spend a period as monks, and for its close ties to the monarchy. A 2015 Gallup International poll found Thailand the most religious of 65 countries surveyed, with 94% of respondents calling themselves religious.
Islam in Pattani, Yala and Narathiwat: Thailand’s Largest Minority
Muslim merchant communities lived in what is now Thailand as early as the 9th century. In the Ayutthaya period a Persian trader from Qom, Sheikh Ahmad, rose to high office, and King Songtham (1611–1628) appointed him the first Chularatchamontri, the title still held by Thailand’s Shaykh al-Islam. Under the Islamic Organ Administration Act of 1997 the Chularatchamontri is appointed by the king on the prime minister’s advice and heads the Central Islamic Council of Thailand, which advises ministries on Islamic affairs. Islamic law applies to Muslims in family and inheritance cases in the four Muslim-majority southern provinces.
Pattani, Yala and Narathiwat, with neighbouring parts of Songkhla, were the core of the Malay Sultanate of Patani, established around 1500 and conquered by Siam in 1785. About two-thirds of Thailand’s Muslims are Thai Malays who speak Kelantan-Pattani Malay. The Krue Se Mosque in Pattani province, whose construction may have begun in the 16th century, is one of the region’s oldest surviving mosques; a Dutch report of 1603 already described Patani’s principal mosque as neatly built of red brick.
In the 2010 census Muslims made up 85.90% of Narathiwat, 84.37% of Pattani, 76.59% of Yala and 67.14% of Satun, and large minorities in Krabi and Songkhla. Yet Muslims are not only a southern community. Thai Ministry of Foreign Affairs research suggests just 18% of Thai Muslims live in the four southernmost provinces, and Bangkok has large Muslim districts such as Nong Chok, Min Buri and Bang Rak. Cham Muslims settled around Ayutthaya and Bangkok from the 15th century, Chinese Hui Muslims worship at the Ban Ho Mosque in Chiang Mai, and families such as the Bunnag trace their descent to Sheikh Ahmad. Most Thai Muslims are Sunni. The Deep South insurgency began in 1948 as a separatist movement in the historically Malay Patani region and has grown more complex and violent since the early 2000s; because religious and ethnic violence there are hard to separate, Freedom House scored Thailand 3 out of 4 for religious freedom in 2023.
Christianity: Ayutthaya’s Portuguese, Bangkok’s Assumption Cathedral and Chiang Mai’s Hills
Portuguese mercenaries and their chaplain reached Ayutthaya in the 1550s, and by 1660 the Vicariate Apostolic of Siam had been set up under Portuguese and French priests. Protestant missionaries arrived in Bangkok in 1828, followed by American Baptists in 1833 and American Presbyterians in 1840. The Presbyterian Laos Mission founded First Church in Chiang Mai in 1868; two converts were killed in a persecution in 1869, and the Edict of Religious Toleration of 1878 eased the pressure.
Catholics, about 400,000 of the country’s Christians in 2015 estimates, are centred on the Assumption Cathedral in Bang Rak, Bangkok. First completed in 1821 under Rama II and rebuilt in Romanesque style between 1910 and 1918, it hosted both papal visits to Thailand, by John Paul II in 1984 and Francis in 2019.
Christianity is strongest in the north. In the 2015 pilot census Christians were 3.43% of the Northern Region against 0.07% of the north-east, and in 2010 they made up 8.82% of Chiang Rai and 7.70% of Chiang Mai, with much higher shares in hill districts such as Mae Sariang in Mae Hong Son. The Department of Religion recognises five Christian bodies: the Catholic Church, the Southern Baptists, the Seventh-day Adventists, the Church of Christ in Thailand and the Evangelical Fellowship of Thailand. Christians have played a large part in Thai health care and education, through hospitals such as Saint Louis and Bangkok Christian Hospital and a network of Christian schools. The government sets a quota of 1,357 foreign Christian missionaries, against six Muslim, 20 Hindu and 41 Sikh.
Brahma at Ratchaprasong and the Pahurat Gurdwara: Hindus and Sikhs
Hinduism shaped Thai religion long before Indian migrants arrived. The Khmer Empire, which ruled much of the region, had strong Hindu roots; Ayutthaya was named after Ayodhya, the birthplace of Rama; the Ramakien, the Thai version of the Ramayana, is the national epic; and Garuda is a symbol of the monarchy. A class of Brahmins still performs rituals for Hindu gods. Many Buddhists pray to Hindu deities, most visibly at the Erawan Shrine at the Ratchaprasong intersection, built in 1956 with a statue of Phra Phrom (Brahma), where worshippers hire dance troupes when their prayers are answered.
The 2010 census counted 41,808 Hindus, mostly of Indian origin and living in the larger cities. The Sri Maha Mariamman Temple on Silom Road, built in 1879 by the Tamil immigrant Vaithi Padayatchi, is the main Tamil Hindu temple. Sikhs trace their community to Ladha Singh, who arrived in 1890; by 1911 more than a hundred Sikh families had settled, mainly in Thonburi, and in 1912 they decided to build a gurdwara, which stands in Bangkok’s Pahurat area and is modelled on the Golden Temple in Amritsar. Sikhs are a small but influential group in retail commerce. A Jewish community of about 2,000, dating back to Baghdadi families in the 17th century, lives mostly in Bangkok.
Guanyin, Yiguandao and Isan Spirits: Faiths the Census Counts as Buddhist
The 93% Buddhist figure hides a good deal of other practice. Many Thai Chinese keep Chinese ancestor worship, Taoism, Confucianism and salvationist movements, but these have no official recognition, their temples are not registered as places of worship and their followers are counted as Theravada Buddhists. Yiguandao, which reached Thailand in the 1970s, had more than 7,000 halls by 2009. Thais of Teochew and Hoklo descent generally honour Guanyin and Mazu, while those of Cantonese origin worship Guan Yu, and festivals such as the Chinese New Year and Qingming are widely celebrated in Bangkok and Chonburi. In Phuket, the Peranakan community holds a nine-day vegetarian festival each September or October devoted to Tua Pek Kong. In the north-east, many Isan people, as well as Northern Thai and Northern Khmer communities, practise Tai folk religion centred on local gods and ancestors alongside their Buddhism.
Understanding these layers starts with the old capitals: the Sri Lankan-style monasteries of the Sukhothai historical park and the ruined royal temples of Ayutthaya, where Persian, Portuguese and Cham communities once lived beside the Buddhist court, show how early Thailand’s religious mix took shape, and the Pali, Sanskrit and Malay words in everyday speech carry the same story into the languages spoken in Thailand today.