Angkor Wat is a Hindu-Buddhist temple complex in Cambodia, located on a site measuring 162.6 hectares (1,626,000 m²; 402 acres). It resides within the ancient Khmer capital city of Angkor. The Guinness World Records considers it as the largest religious structure in the world. Originally constructed as a Hindu temple dedicated to the god Vishnu for the Khmer Empire by King Suryavarman II during the 12th century, it was gradually transformed into a Buddhist temple towards the end of the century; as such, it is also described as a "Hindu-Buddhist" temple.

Angkor Wat was built at the behest of the Khmer King Suryavarman II in the early 12th century in Yaśodharapura (Khmer: យសោធរបុរៈ, present-day Angkor), the capital of the Khmer Empire, as his state temple and eventual mausoleum. Angkor Wat combines two basic plans of Khmer temple architecture: the temple-mountain and the later galleried temple. It is designed to represent Mount Meru, home of the devas in Hindu mythology: within a moat more than 5 kilometres (3 mi) long and an outer wall 3.6 kilometres (2.2 mi) long are three rectangular galleries, each raised above the next. At the centre of the temple stands a quincunx of towers. Unlike most Angkorian temples, Angkor Wat is oriented to the west; scholars are divided as to the significance of this. The temple is admired for the grandeur and harmony of the architecture, its extensive bas-reliefs, and for the numerous devatas adorning its walls. The modern name Angkor Wat, alternatively Nokor Wat, means "Temple City" or "City of Temples" in Khmer. Angkor (អង្គរ ângkôr), meaning "city" or "capital city", is a vernacular form of the word nokor (នគរ nôkôr), which comes from the Sanskrit/Pali word nagara (Devanāgarī: नगर) Wat (វត្ត vôtt) is the word for "temple grounds", also derived from Sanskrit/Pali vāṭa (Devanāgarī: वाट. meaning "enclosure".

The original name of the temple was Vrah Viṣṇuloka or Parama Viṣṇuloka meaning "the sacred dwelling of Vishnu". Angkor Wat lies 5.5 kilometres (3+1⁄2 mi) north of the modern town of Siem Reap, and a short distance south and slightly east of the previous capital, which was centred at Baphuon. In an area of Cambodia where there is an essential group of ancient structures, it is the southernmost of Angkor's main sites.