The ukulele, sometimes abbreviated to uke, is a member of the guitar family of instruments; it generally employs four nylon or gut strings or four courses of strings.

The ukulele originated in the 19th century as a Hawaiian interpretation of the machete, a small guitar-like instrument related to the cavaquinho, braguinha and the rajao, taken to Hawaii by Portuguese immigrants. It gained great popularity elsewhere in the United States during the early 20th century, and from there spread internationally.

The tone and volume of the instrument varies with size and construction. Ukuleles commonly come in four sizes: soprano, concert, tenor, and baritone.