The KLF (also known as The Justified Ancients of Mu Mu, The Timelords and other names) were one of the seminal bands of the British acid house movement during the late 1980s and early 1990s.

Beginning in 1987, Bill Drummond (alias King Boy D) and Jimmy Cauty (alias Rockman Rock) released hip hop-inspired and sample-heavy records as The Justified Ancients of Mu Mu, and on one occasion (the British number one hit single "Doctorin' the Tardis") as The Timelords. The KLF released a series of international hits on their own KLF Communications record label, and became the biggest-selling singles act in the world for 1991. The duo also published a cynical book, The Manual (How to Have a Number One the Easy Way), and worked on a road movie called The White Room.