Vihara is a Sanskrit and Pali word designating a Buddhist monastery.

"Vihara" originally meant "dwelling" or "refuge", such as those used by wandering monks during the rainy season.

As permament monasteries became established, the name "Vihara" was kept. Some Viharas became extremely important institutions, some of them evolving into major Buddhist Universities with thousands of students, such as Nalanda.

Life in "Viharas" was codified early on, and is the object of a part of the Pali canon, the Vinaya Pitaka or "Basket of monastic discipline".

The northern Indian state of Bihar derives its name from the workd "Vihara", probably due to the abundance of Buddhist monasteries in that area.

In Thailand, "Vihara" has a narrower meaning, and designates a shrine hall.