Psychedelia in music (or also psychedelic music, less formally) is a term that refers to a broad set of popular music styles, genres and scenes, that may include psychedelic rock, psychedelic folk, psychedelic pop, psychedelic soul, psychedelic ambient, psychedelic trance, psychedelic techno, and others. Psychedelic rock is also commonly called acid rock. Psychedelia can occur in almost every genre of music, including classical Western art music.

Psychedelic rock evolved in the 60s as an offshoot of the rock and roll movement combining elements of rock, reggae, and other diverse elements. Inspired by the use of mind altering drugs like cannabis, mescaline, psilocybin, and especially LSD, psychedelic rock broke with traditional rock and laid the roots for psychedelic metal and experimental rock genres. In the USA bands like The Doors, the Grateful Dead, and Jefferson Airplane lead the way for later bands like 13th Floor Elevators, Bubble Puppy, and Third Bardo to name a few. In 1965-1967 The Beatles also were recording psychedelic rock with tunes like "Lucy in the Sky with Diamonds" and "Tomorrow Never Knows" to name a few, but were not strictly classified as psychedelic rock. Cream and Pink Floyd (with original founder Syd Barrett) embraced psychedelic music fully becoming two of the first truly psychedelic bands.