A Fretless Guitar (frɛ́t lɛ́s gətɑ́r) is a guitar that has no frets, making the fretboard a flat smooth surface. Fretless guitars generate a different sound than their fretted counterparts, since the guitar players’ fingertips absorb a lot more of the string’s energy which would be normally displaced by a metal fret. Also, because a fretless guitar does not have frets as note indicators, fretless guitar players are not limited to the traditional 12-tone scale.

Fretless guitars require much more technique and ear training, as the player needs to be much more in tune with where to finger each note. Fretless guitars themselves are uncommon in Western music, but the fretless electric bass guitar has seen widespread popularity, especially in Jazz, R&B and funk.