A bass instrument with a hollow wooden body similar to, though usually somewhat larger than a steel-string acoustic guitar. Like the traditional electric bass and the double bass, the acoustic bass guitar commonly has 4 strings, which are normally tuned EADG, an octave below the lowest 4 strings of the 6-string guitar. The majority of acoustic basses are fretted, but a significant number are fretless. Because it can be difficult to hear an acoustic bass guitar without an amplifier, even in settings with other acoustic instruments, most acoustic basses have pickups, either magnetic or piezo-electric or both, so that they can be amplified.

Traditional music of Mexico features several varieties of acoustic bass guitars, such as the bajo sexto, with 6 pairs of strings, and the guitarrón or chitarrone, a very large, deep-bodied 6-string acoustic bass guitar played in mariachi bands.

The first modern acoustic bass guitar was developed in the early 1960s by Ernie Ball of San Luis Obispo, California. Ball's aim was to provide bass guitarists with a more acoustic-sounding instrument that would match better with the sound of acoustic guitars.

Ball collaborated with George Fullerton, a former employee at Fender, to develop the Earthwood acoustic bass guitar, which was introduced in 1972. Production of this instrument ceased in 1974, resuming a few years later under the direction of Ernie Ball employee Dan Norton, until production finally ended again in 1985. The Earthwood acoustic bass guitar was quite large (and deep) in contrast to most instruments in current production, which gave it more volume, especially in the low register. The instrument was little used in acoustic musical performances until the late 1980s, when the acoustic basses were used in performances on the MTV Unplugged television programme.