The guitar solo as a distinct, improvised, or composed musical feature emerged gradually from the blues and jazz traditions of the early 20th century, rather than from a single inventor or moment. Its roots lie in the blues guitarists of the 1920s and 1930s who began extending their melodic lines beyond the standard vocal accompaniment, often playing "breaks" or "riffs" between vocal lines.

However, the modern concept of the dedicated guitar solo is most strongly associated with Jazz guitarists in the 1930s and 40s. Django Reinhardt, a Romani-French jazz guitarist, is often credited as a pioneer who elevated the instrumental solo to a high art form, showcasing complex improvisation and technical virtuosity. In the US, Charlie Christian (with the Benny Goodman Orchestra) is frequently cited as the first electric guitar soloist to gain mainstream attention, proving the electric guitar could function as a lead voice in a big band setting.

By the 1950s and 1960s, the electric guitar solo became the centerpiece of rock and roll and blues-rock. Artists like B.B. King, Jimi Hendrix, and Eric Clapton transformed the solo from a decorative element into a primary vehicle for emotional expression and technical innovation, cementing its place in popular music history.