A solid-body instrument is a string instrument such as a guitar, bass or violin built without its normal sound box and relying on an electric pickup system to directly receive the vibrations of the strings.

Solid-body instruments are preferred in situations where acoustic feedback may otherwise be a problem and are inherently both less expensive to build and more rugged than acoustic electric instruments.

The most well-known solid body instruments are the electric guitar and electric bass. These instruments were instrumental in creating new genres of music such as rock and metal. Common materials used in the construction of solid body instruments are alder, maple, mahogany, korina, spruce, rosewood, and ebony. Some woods are used more in constructing certain solid bodies more than others. For instance, mahogany, maple, alder, spruce, and rosewood are commonly used in constructing the parts of electric guitars and bass guitars.

Solid body instruments have some of the same features as acoustic string instruments. Like a typical string instrument they have a tuner and a bridge and a fingerboard (or fretboard). Fretboards are a piece of wood that run from top of the neck to the body. Atop the fretboard are the strings. Some fingerboards have frets or bars which the strings are pressed against. This allows musicians to stop the string in the same place. Ebony, rosewood and maple are commonly used to make the fingerboard. All the solid bodies have variations in scale length or, the length of the strings from the nut to the bridge. The action, or the height of the strings from the fingerboard, is adjustable on solid body instruments. Most solid bodies have a form of equalization controls such as a preamp, volume and tone controls. Some might also contain frequency adjustments such as low, middle, and high. These are used to shape the sound along with the aid of amplifier. Amplifiers allow solid body instruments to be heard at medium to high volumes.