A psaltery is an ancient member of the zither family. Its body consists of almost entirely of a wooden sound board or resonating box. Wire strings are usually attached to wooden or metal pegs at either end of its body.

It may date back to 300 BC or earlier, when an instrument with the same name was used for praise and celebration in ancient Greece. Centuries later in western Europe and Great Britain, psalteries were frequently used by minstrels, amateurs, and professional musicians at least until the 1600s. During that century, these instruments inspired new creations such as the hammered dulcimer and, very possibly, the harpsichord (another form of box zither which has strings that are similarly attached but operated by a keyboard).

To play the European psaltery, the body of the instrument is held against the chest, which acts as a resonator to amplify the sound. Generally, the strings are plucked with the fingers or with a plectrum (pick) or sometimes a pair of quill plectra, although some more modern psalteries are bowed.

Comparable instruments found throughout the Islamic world include the Turkish qanun, which has up to 72 strings, and the Javanese tjelempung (or celempung), a virtuousic improvising instrument used in the Gamelan. In Asia, the Chinese yang chi'in, which may have originated as early as 2000 BC, and the Japanese koto, the chief of contemporary Japanese traditional instruments, are other relatives of the psaltery and zither.