A semi-acoustic guitar, also known as a hollow-body electric guitar, is a type of electric guitar designed to be played with a guitar amplifier featuring a fully or partly hollow body and at least one electromagnetic pickup. First created in the 1930s, they became popular in jazz and blues, where they remain widely used, and the early period of rock & roll, though they were later largely supplanted by solid-body electric guitars in rock.

An electric guitar is a guitar that requires external amplification in order to be heard at typical performance volumes, unlike a standard acoustic guitar. It uses one or more pickups to convert the vibration of its strings into electrical signals, which ultimately are reproduced as sound by loudspeakers. The sound is sometimes shaped or electronically altered to achieve different timbres or tonal qualities from that of an acoustic guitar via amplifier settings or knobs on the guitar. Often, this is done through the use of effects such as reverb, distortion and "overdrive"; the latter is considered to be a key element of electric blues guitar music and jazz, rock and heavy-metal guitar-playing. Designs also exist combining attributes of the electric and acoustic guitars: the semi-acoustic and acoustic-electric guitars.