Free-reed instruments are musical instruments that produce sounds from a reed vibrating in a chamber, as opposed to "fixed reed" instruments, which use a vibrating reed to set a column of air in vibration.

In a free reed instrument, it is the physical characteristics of the reed itself, such as length, cross-sectional area and stiffness, that determine the pitch (frequency) of the musical note produced. This contrasts with the situation in fixed reed instruments where the pitch is determined by the length of the column of air which vibrates in sympathy with the reed.

The oldest known free-reed instrument is the Chinese sheng, widely accepted as the musical ancestor of the harmonica and accordion. Other well-known free-reeds include the concertina, bandoneon, melodica, and reed organ.