Disco is the second album by the UK electronic music group Pet Shop Boys. It was released by Parlophone on November 17, 1986 (1986-11-17).

Disco was not an original studio album, but rather a collection of remixes of tracks from their first album, Please, and its respective B-sides. Many fans of 1980s synthpop view the mixes on this album as some of the best examples of the extended dance mix, and this album includes remixes by Arthur Baker, Shep Pettibone and Pet Shop Boys themselves.

It is difficult to say where Pet Shop Boys saw this album fitting in among their other albums when they released it. In 2001, when they re-released what they deemed their first six albums, Disco was not included.

In addition, Pet Shop Boys would later release the remix albums Disco 2, Disco 3 and Disco 4, although the concepts of these compilations differ greatly from the original Disco album: Disco 2 is a continuous mega-mix of dance remixes, Disco 3 is a mixture of remixes and new songs and Disco 4 consists exclusively of tracks remixed by the Pet Shop Boys, mainly by other artists.

Disco is a genre of dance music. Disco acts charted high during the mid-1970s, and the genre's popularity peaked during the late 1970s. Its initial audiences were club-goers from the African American, Latino, gay, and psychedelic communities in New York City and Philadelphia during the late 1960s and early 1970s. Disco also was a reaction against both the domination of rock music and the stigmatization of dance music by the counterculture during this period. Women embraced disco as well, and the music eventually expanded to several other popular groups of the time.

In what is considered a forerunner to disco style clubs, New York City DJ David Mancuso opened The Loft, a members-only private dance club set in his own home, in February 1970.Allmusic claims some have argued that Isaac Hayes and Barry White were playing what would be called disco music as early as 1971. According to the music guide, there is disagreement as to what the first disco song was. Claims have been made for Manu Dibango's "Soul Makossa" (1972), Jerry Butler's "One Night Affair" (1972), the Hues Corporation's "Rock the Boat" (1973), George McCrae's "Rock Your Baby" (1974), and "Kung Fu Fighting" (1974) by Biddu and Carl Douglas. The first article about disco was written in September 1973 by Vince Aletti for Rolling Stone magazine. In 1974 New York City's WPIX-FM premiered the first disco radio show.

An album may be understood as a collection of recordings, released as a single package on gramophone record, cassette, compact disc, or via digital distribution, however the concept is found in printed music dating into the early nineteenth century in works by composers such as Schumann and Mendelssohn. The word derives from the Latin word for list.

Today, with the vinyl record no longer being used as the primary form of distribution, the term "album" can still be applied to any sound recording collection, such as those on compact disc, MiniDisc, Compact audio cassette, and digital or MP3 albums.Cover art is also considered an integral part of the album. Many albums also come with liner notes and inserts giving background information or analysis of the recording, reprinted lyrics, images of the performers, or additional artwork and text. These are now often found in the form of CD booklets.

Vinyl LP records have two sides, each comprising one half of the album. If a pop or rock album contained tracks released separately as commercial singles, these were often traditionally placed in particular positions on the album. A common configuration was to have the album led off by the second and third singles, followed by a ballad. The first single would lead off side 2. In the past many singles (such as the Beatles' "Hey Jude" and Bob Dylan's "Positively 4th Street") did not appear on albums, but others (such as the Beatles' "Come Together" and Dylan's "Like a Rolling Stone") were part of an album released concurrently. Today, many commercial albums of music tracks feature one or more singles, which are released separately to radio, TV or the Internet as a way of promoting the album. Albums have also been issued that are compilations of older tracks not originally released together, such as singles not originally found on albums, b-sides of singles, or unfinished "demo" recordings.