电贝斯（英语：electric bass），又称为贝斯吉他、低音吉他（英语：bass guitar），简称贝斯，现代摇滚乐团组合的主要乐器。一般乐队中除了电贝斯手以外，还有一位吉他手、一位键盘手、一位鼓手、及一位主音歌手。电贝斯是从低音提琴演变出来的，空弦由粗至细为E、A、D、G。

而且在乐队中，电贝斯在节奏上扮演一个重要的角色。电贝斯的弹奏主要是拨弦、slapping和使用拨片。形状上和构造上都和电吉他相似，但是本体大一点、颈部更长，还有更宽阔的音域。四弦电贝斯最低音的弦比吉他最低音的弦低完全八度。

The bass guitar (also called electric bass, or simply bass) is a stringed instrument played primarily with the fingers or thumb, by plucking, slapping, popping, strumming, tapping, thumping, or picking with a plectrum, often known as a pick.

The bass guitar is similar in appearance and construction to an electric guitar, but with a longer neck and scale length, and four to six strings or courses. The four-string bass, by far the most common, is usually tuned the same as the double bass, which corresponds to pitches one octave lower than the four lowest pitched strings of a guitar (E, A, D, and G). The bass guitar is a transposing instrument, as it is notated in bass clef an octave higher than it sounds (as is the double bass) to avoid excessive ledger lines. Like the electric guitar, the bass guitar has pickups and it is plugged into an amplifier and speaker for live performances.