The Jew's harp, also known as jaw harp, juice harp, or mouth harp, is a lamellophone instrument, consisting of a flexible metal or bamboo tongue or reed attached to a frame. Despite the colloquial name, the Jew's harp most likely originated in Siberia, specifically in or around the Altai Mountains, and is of Turkic origin and has no relation to the Jewish people.

A lamellophone is a member of the family of musical instruments that makes its sound by a thin vibrating plate called a lamella or tongue, which is fixed at one end and has the other end free. When the musician depresses the free end of a plate with a finger or fingernail, and then allows the finger to slip off, the released plate vibrates. An instrument may have a single tongue or a series of multiple tongues.