A wat (Khmer: វត្ត wōat; Lao: ວັດ vat; Thai: วัด, RTGS: wat, pronounced [wát]; Tai Lü: 「ᩅᨯ᩠ᨰ」(waD+Dha); Northern Thai: 「ᩅ᩠ᨯ᩶」 （w+Da2)) is a type of Buddhist temple and Brahminical temple in Cambodia, Laos, East Shan State, Yunnan and Thailand. The word wat is a thai word that was borrowed from Sanskrit vāṭa (Devanāgarī: वाट), meaning 'enclosure'.^[1][2] The term has varying meanings in each region, sometimes referring to a specific type of government-recognised or large temple, other times referring to any Buddhist or Brahminical temple.

Strictly speaking, a wat is a Buddhist sacred precinct with vihara (quarters for bhikkhus), a temple, an edifice housing a large image of Buddha and a facility for lessons. A site without a minimum of three resident bhikkhus cannot correctly be described as a wat although the term is frequently used more loosely, even for ruins of ancient temples. As a transitive or intransitive verb, wat means to measure, to take measurements; compare templum, from which temple derives, having the same root as template.

In Cambodia, a wat is any place of worship. "Wat" generally refers to a Buddhist place of worship, but the precise term is វត្តពុទ្ធសាសនា wat putthasasana. Angkor Wat អង្គរវត្ត means 'city of temples'.

In everyday language in Thailand, a "wat" is any place of worship except a mosque (Thai: สุเหร่า; RTGS: surao; or Thai: มัสยิด; RTGS: matsayit) or a synagogue (Thai: สุเหร่ายิว; RTGS: surao yio). Thus, a wat chin (วัดจีน) or san chao (ศาลเจ้า) is a Chinese temple (either Buddhist or Taoist), wat khaek (วัดแขก) or thewasathan (เทวสถาน) is a Hindu temple and bot khrit (โบสถ์คริสต์) or wat farang (วัดฝรั่ง) is a Christian church, though Thai โบสถ์ (RTGS: bot) may be used descriptively as with mosques.

Almost all Buddhist temples in Cambodia were built in Khmer architectural style. Most temples were finely decorated with a spiked tower (bosbok) (Khmer: បុស្បុក)(some temples have three or five spiked towers; some have none) on the rooftop along with pediments, naga heads, and chovear (Khmer: ជហ្វា) (a decorative ridge-piece that is placed at each topmost edge of the roof, just above the tip of each pediment). Below the edge of the roof and at the top of external columns, garuda or kinnari figures are depicted supporting the roof. There are a pair of guardian lions and one head or several (three, five, seven, or nine). naga sculptures are beside each entrance of the temple. Inside the main temple (vihara) and the multipurpose hall (lunch hall), mural paintings depict the life of Gautama Buddha and his previous life.

At the end of 2017, there were 4,872 wats with 69,199 Buddhist monks supporting Buddhism in Cambodia.^[5] As of 2010 it was estimated that 96.9 percent of the Cambodian population was Buddhist.^[6]

Despite having only 3.8 percent Buddhists in Kelantan, the northern Malaysian state of Kelantan has numerous Thai wats.^[7]

As of 2016 Thailand had 39,883 wats. Three hundred-ten were royal wats, the remainder were private (public). There were 298,580 Thai Buddhist monks, 264,442 of the Maha Nikaya order and 34,138 of the Dhammayuttika Nikaya order. There were 59,587 Buddhist novice monks.^[8]

Wat Pah Nanachat (Bung Wai International Forest Monastery), established in 1975 by Ajahn Chah as a training community for non-Thais and foreigners, the primary language of instruction is English.