Also known as a Spanish guitar, a member of the guitar family used in classical music. An acoustic wooden string instrument with strings made of gut or nylon, it is a precursor of the modern acoustic and electric guitars, both of which use metal strings. Classical guitars are derived from the Spanish vihuela and gittern in the 15th and 16th centuries, which later evolved into the 17th and 18th century baroque guitar and later the modern classical guitar in the mid 19th century.

For a right-handed player, the traditional classical guitar has 12 frets clear of the body and is properly held on the left leg, so that the hand that plucks or strums the strings does so near the back of the sound hole (this is called the classical position). The modern steel string guitar, on the other hand, usually has 14 frets clear of the body and is commonly played off the hip. 

The term modern classical guitar is sometimes used to distinguish the classical guitar from older forms of guitar, which are in their broadest sense also called classical, or more specifically, early guitars. Examples of early guitars include the 6-string early romantic guitar (c. 1790–1880), and the earlier baroque guitars with 5 courses.

The materials and methods of classical guitar construction may vary, but the typical shape is either modern classical guitar or that historic classical guitar similar to the early romantic guitars of France and Italy. Classical guitar strings once made of gut are now made of such polymers as nylon, with fine wire wound about the acoustically lower (bass side) strings.

The flamenco guitar derives from the modern classical, but has differences in material, construction and sound.