(from Old French flageol: “pipe,” or “tabor pipe”), wind instrument closely related to the recorder. Like the recorder it is a fipple, or whistle, flute—i.e., one sounded by a stream of breath directed through a duct to strike the sharp edge of a hole cut in the side of the pipe. The name flageolet was applied to such flutes at least from the 13th century, but from the late 16th century it has referred most specifically to a form of the instrument developed at that time in Paris. Its principal, or French, form has a contracting bore with four front finger holes and two back thumbholes. From the mid-18th century the beaked mouthpiece formerly used was replaced by a narrow tube of bone or ivory that led to a chamber maintaining steady air pressure and holding a sponge to absorb breath moisture.

A popular amateur instrument, it also occupied in the 18th-century orchestra (as the flauto piccolo) the role now held by the modern piccolo. With keywork added it became the popular quadrille flageolet of the mid-19th century, made famous by the virtuoso Collinet. The English flageolet is a late 18th-century adaptation of the French form, with six front finger holes and, sometimes, keywork. Flageolets were often built as double pipes (the English also as triple pipes), all with a single mouthpiece.

The flageolet's compass varied but, in the 19th century, was typically from the second G above middle C to the fourth A above and was notated a 12th below. “Flageolet” sometimes refers generically to any fipple flute.