"Interstellar Overdrive" is a psychedelic composition by Pink Floyd, which appears on their 1967 debut album The Piper at the Gates of Dawn at almost ten minutes in length. An earlier, longer recording can be heard on the soundtrack to the film Tonite Let's All Make Love in London, which was released in the same year. Other versions of the track appear on various bootleg recordings.

Like the Paul Butterfield Blues Band's slightly earlier song "East-West," "Interstellar Overdrive" was one of the very first psychedelic instrumental improvisations recorded by a rock band. It was seen as Pink Floyd's first foray into space rock (along with "Astronomy Domine"), although band members would later disparage this term. Despite its encapsulation of their concert repertoire under the leadership of guitarist and composer Syd Barrett, the long, improvisational, freeform structure of the piece is not particularly reflective of the group's recorded output. As drummer Nick Mason states in his book Inside Out: A Personal History of Pink Floyd, live versions of the song featured many "sections" that did not appear on the album, and would often last more than 20 minutes. During the band's days playing in residence at London underground clubs such as the UFO (Underground Freak Out), the song usually opened their show. It occupied other positions, including the encore, until it was retired from the band's setlist in 1970.