The vihuela (Spanish pronunciation: [viˈwela]) is a 15th-century fretted plucked Spanish string instrument, shaped like a guitar (figure-of-eight form offering strength and portability) but tuned like a lute. It was used in 15th- and 16th-century Spain as the equivalent of the lute in Italy and has a large resultant repertory. There were usually five or six^{[citation needed]} doubled strings.

A bowed version, the vihuela de arco (arco meaning bow), was conceived in Spain and made in Italy from 1480. One consequence was the phrase vihuela de mano being thereafter applied to the original plucked instrument. The term vihuela became "viola" in Italian ("viole" in Fr.; "viol" in Eng.), and the bowed vihuela de arco was to serve as a prototype in the hands of the Italian craftsmen for the "da gamba" family of fretted bowed string instruments, as developed starting in 1480. Their vihuela-inherited frets made these easier to play in tune than the rebec family (precursors of the "da braccio" family), and so they became popular for chamber music.

The vihuela, as it was known in Spanish, was called the viola de mà in Catalan, viola da mano in Italian and viola de mão in Portuguese. The two names are functionally synonymous and interchangeable. In its most developed form, the vihuela was a guitar-shaped instrument with six double-strings (paired courses) made of gut. Vihuelas were tuned identically to their contemporary Renaissance lute; 4ths and one major 3rd (44344, almost like a modern guitar tuning, with the exception of the third string, which was tuned a semitone lower).

Plucked vihuelas, being essentially flat-backed lutes, evolved in the mid-15th century, in the Kingdom of Aragón, located in north-eastern Iberia (Spain). In Spain, Portugal, and Italy the vihuela was in common use by the late 15th through to the late 16th centuries. In the second half of the 15th century, some vihuela players began using a bow, leading to the development of the viol.

There were several different types of vihuela (or different playing methods at least):

Tunings for 6 course vihuela de mano (44344):

Although mainstream use of the vihuela has faded away, traces of the complex polyphonic music that was its repertoire in the late 16th century, along with the other primary instrument of the Spanish and Portuguese Renaissance, the cross-strung harp, both of which can be heard in Mexican Mariachi music. The vihuela's descendants that are still played are the violas campaniças of Portugal. Much of the vihuela's place, role, and function was taken up by the subsequent Baroque guitar (also sometimes referred to as vihuela or bigüela). Currently, the vihuela is in widespread use in Mexican Mariachi music, where its distinctive sound is featured in solos. Additionally, the vihuela is used for the performance of early music, using modern replicas of historical instruments. Today, instruments like the tiple are descendants of vihuelas brought to America in the 16th century.

Vihuela bodies were lightly constructed from thin flat slabs or pieces of wood, bent or curved as required. This construction method distinguished them from some earlier types of string instruments whose bodies (if not the entire instrument including the neck) were carved out from a solid single block of wood. The back and sides of common lutes were also made of pieces however, being multiple curved or bent staves joined and glued together to form a bowl, made from cypress with a spruce or cedar top.