The bow frog is the end part of a stringed musical instrument's bow that encloses the mechanism responsible for tightening and holding the bow hair ribbon. Most of the bow frogs used in today's classical bows are made of ebony; some synthetic bows have frogs made with materials that imitate ebony, while Baroque bows use frogs made with various woods.

In music, a bow is a tensioned stick which has hair coated in rosin affixed to it. It is moved across some part of a musical instrument to cause vibration, which the instrument emits as sound. The vast majority of bows are used with string instruments, such as the violin, viola, cello, and bass, although some bows are used with musical saws and other bowed idiophones.