Keith John Moon (23 August 1946 – 7 September 1978) was an English drummer who played with the English rock band the Who. He was noted for his unique style and his eccentric, often self-destructive behaviour. In 2011, Moon was voted the second-greatest drummer in history by a Rolling Stone readers' poll. His drumming continues to be praised by critics and musicians.

Moon grew up in Alperton a suburb of Wembley, northwest London, and took up the drums during the early 1960s. After playing with a local band, the Beachcombers, he joined the Who in 1964 before they recorded their first single. Moon remained with the band during their rise to fame, and was quickly recognised for his drumming style, which emphasised tom-toms, cymbal crashes, and drum fills. He occasionally collaborated with other musicians and later appeared in films, but considered playing in the Who his primary occupation and remained a member of the band until his death. In addition to his talent as a drummer, however, Moon developed a reputation for smashing his kit on stage and destroying hotel rooms on tour. He was fascinated by blowing up toilets with cherry bombs or dynamite, and by destroying television sets. Moon enjoyed touring and socialising, and was bored and restless when the Who were inactive. His 21st birthday party in Flint, Michigan, has been cited as a notorious example of decadent behaviour by rock groups.