The province is named after the temple of Prasat Preah Vihear. The Dângrêk Mountains and the Cambodia/Thailand border are in the north of Preah Vihear province.
Preah Vihear is one of the nine provinces that are part of the Tonle Sap Biosphere Reserve.
On 15 April 2016, Preah Vihear recorded a temperature of 42.6 °C (108.7 °F), which is the highest temperature to have ever been recorded in Cambodia.