The tambouras (Greek: ταμπουράς [tabuˈras]) is a Greek traditional string instrument of Byzantine origin. It has existed since at least the 10th century, when it was known in Assyria and Egypt. At that time, it might have had between two and six strings. The characteristic long neck bears two strings, tuned five notes apart.

It is also similar to the Turkish tambur and Indian tanpura.

Tanbur, a Persian word, is according to some scholars derived from the Sumerian pan tur, meaning "little bow".

It is considered that the tambouras' ancestor is the ancient Greek pandouris, also known as pandoura, pandouros or pandourida (πανδουρίς, πανδούρα, πάνδουρος), from which the word is derived. The tambouras is mentioned in the Byzantine epic of Digenis Akritas, when the hero plays his θαμπούριν, thambourin (medieval form of tambouras):

Και αφότου αποδείπνησεν, εμπαίνει εις το κουβούκλιν

και επήρεν το θαμπούριν του και αποκατάστησέν το.

When he had finished his meal, he entered his chamber

and picked up his tamboura [thambourin] and tuned it.