The Preah Vihear Temple or  (Khmer: , Prasat Preah Vihear) is a Khmer temple situated atop a 525-metre (1,720 ft) cliff in the Dângrêk Mountains, in the Preah Vihear province of northern Cambodia and near the border of the Kantharalak district (amphoe) in the Sisaket province of eastern Thailand. In 1962, following a significant dispute between Thailand and Cambodia over ownership of the temple, the International Court of Justice (ICJ) in The Hague awarded the ownership to Cambodia.

Affording a view for many kilometers across a plain, Prasat Preah Vihear has the most spectacular setting of all the temples built during the six-centuries-long Khmer Empire. As a key edifice of the empire's spiritual life, it was supported and modified by successive kings and so bears elements of several architectural styles. Preah Vihear is unusual among Khmer temples in being constructed along a long north-south axis, rather than having the conventional rectangular plan with orientation toward the east. The temple gives its name to Cambodia's Preah Vihear province, in which it is now located, as well as the Khao Phra Wihan National Park which borders it in Thailand's Sisaket province, through which the temple is most easily accessible. On July 7, 2008, Preah Vihear was listed as a UNESCO World Heritage Site.