A guitar solo is a melodic passage, instrumental section, or entire piece of music written for a classical guitar, electric guitar or an acoustic guitar. In 20th and 21st century traditional music and popular music such as blues, swing, jazz, jazz fusion, rock and metal guitar solos often contain virtuoso techniques and varying degrees of improvisation. Guitar solos on classical guitar, which are typically written in musical notation, are also used in classical music forms such as chamber music and concertos.

Guitar solos range from unaccompanied works for a single guitar to compositions with accompaniment from a few other instruments or a large ensemble. The accompaniment musicians for a guitar solo can range from a small ensemble such as a jazz quartet or a rock band, to a large ensemble such as an orchestra or big band. Unaccompanied acoustic guitar music is found in folk and classical music dating as far back as the instrument has existed, and the use of an acoustic guitar as a solo voice within an ensemble dates back at least to the Baroque concerto.