Plunderphonics is a music genre in which tracks are constructed by sampling recognizable musical works. The term was coined by composer John Oswald in 1985 in his essay "Plunderphonics, or Audio Piracy as a Compositional Prerogative", and eventually explicitly defined in the liner notes of his Grayfolded album. Plunderphonics is a form of sound collage. Oswald has described it as a referential and self-conscious practice which interrogates notions of originality and identity.

Although the concept of plunderphonics is broad, in practice there are many common themes used in what is normally called plunderphonic music. This includes heavy sampling of educational films of the 1950s, news reports, radio shows, or anything with trained vocal announcers. Oswald's contributions to this genre rarely used these materials, the exception being his rap-like 1975 track "Power".

The process of sampling other sources is found in various genres (notably hip-hop and especially turntablism), but in plunderphonic works, the sampled material is often the only sound used. These samples are usually uncleared and sometimes result in legal action being taken due to copyright infringement. Some plunderphonic artists use their work to protest what they consider to be overly restrictive copyright laws. Many plunderphonic artists claim their use of other artists' materials falls under the fair use doctrine.

Development of the process is when creative musicians plunder an original track and overlay new material and sounds on top until the original piece is masked and then removed, though often using scales and beats. It is a studio-based technique used by such groups as the American experimental band The Residents (who used Beatles tracks), and other noted exponents including DJ Shadow, 808 State and The Avalanches.