Lamellaphone describes any of a family of musical instruments. The name comes from the Latin root "lamella" for "plate", and the Greek root "phone" for "sound". The name derives from the way the sound is produced: the instrument has a series of thin plates, or "tongues", each of 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, and then allows the finger to slip off, the released plate vibrates. A tongue may be plucked either from the top or from the bottom.

Lamellaphones are a category of plucked idiophones; included in this category are the African "thumb-pianos" described below, as well as the various forms of Jew's Harp and the European mechanical music box.

A large number of lamellaphones originate in Africa, where they are known under the names sanza, kisanji, likembe, mbira, mbila, and kalimba. They were reported as early as in the 16th century, but there is no doubt they have a much longer history. The Caribbean marimbula is also of this family.

The tongues may be arranged in the manner of a piano and may be made small enough to play with individual fingers, hence the colloquial name "thumb piano".

Some conjecture that African lamellaphones were derived from xylophones and marimbas. However, similar instruments have been found elsewhere; for example, the indigenous peoples of Siberia know primitive wooden and metallic lamellaphones with a single tongue.

Lamellaphones may be made with or without resonators.