In the field of rock music, overdriven is a term used for an electric guitar amplifier when turned up, usually deliberately, past its maximum possible output, to the point where distortion (clipping) is clearly audible in the output signal. This distortion may range from a slight added "edge" with some increase in sustain, up to a thick fuzzy sound whose tonality is almost unrecognisable as that of the input signal.

Many modern guitar amplifiers have a "pre-amp" stage which can be made to distort heavily, whilst the final output volume can be controlled by changing the gain on the later stage(s) of amplification. The distorted sound from an overdriven electric guitar amplifier is usually much more acceptable to the ear than the distortion which most other modern audio amplifiers would create.