Shoom was a weekly all-nighter dance music event in London, England, between September 1987 and early 1990. It is widely credited with initiating the acid house movement in the UK. Shoom was founded by Danny Rampling, then an unknown DJ and record producer, and managed by his wife Jenni. The club began at a 300-capacity basement gym on Southwark Street in South London. By May 1988, its growing popularity necessitated a move to the larger Raw venue on Tottenham Court Road, Central London, and a switch from Saturday to Thursday nights. Later relocations were to The Park Nightclub, Kensington and Busby's venue on Charing Cross Road.

The early nights featured Danny Rampling and Terry Farley as the in-house DJs, playing a mixture of Chicago house, Balearic and Detroit techno, mixed with contemporary pop and post-punk music. The club favoured modern, minimalist architectural interior designs, filled with strawberry-scented smoke machines and strobe lights. Its musical and visual culture evolved around the psychedelic drug LSD, and MDMA, an empathogen commonly known in the UK as ecstasy or "E". Over time, regular guest DJs included Carl Cox, Mark Moore and Andrew Weatherall.

Within weeks of its opening, far more people were trying to get into Shoom than the venue could hold. The Ramplings were forced to adopt a strict entrance policy, with Jenni taking on the unpopular role of doorman. Shoom closed early in 1990 after drug use at the club began to attract police attention. By this time, electronic music had crossed into the mainstream as the heavier sounding rave style became popular, making Shoom appear outdated.

English DJ and record producer Paul Oakenfold spent the summer of 1985 in Ibiza, where he met DJs Trevor Fung and Ian St. Paul. To celebrate his birthday, Oakenfold hired an island villa and invited the London DJs Nicky Holloway, Johnnie Walker, and the then-unknown Danny Rampling. While there, Rampling took ecstasy for the first time and was deeply impressed by the music and atmosphere at Alfredo Fiorito's open-air and after-hours Amnesia nightclub and at Pepe Rosello's Space.

Neither Danny nor Jenni had experience in organising nightclubs. However, upon returning to England, they sought to recreate the atmosphere of the Balearic beat clubs they had seen in Ibiza. The couple was described by journalist Louise Gray as a "very ordinary, upwardly mobile working class couple" from Bermondsey, in South East London. Shoom opened around the same time as the two other early acid house clubs in London: Holloway's Balearic The Trip (from June 1987), and Oakenfold's house-focused Spectrum (from April 1988 until 1990 at Heaven on Charing Cross).

Shoom's name was inspired by a phrase Rampling heard from Fung in Ibiza when describing the effects of "rushing" on ecstasy. The opening night was held on a Saturday in November 1987, and titled "Klub Schoom", but this was shortened to "Shoom" by the second night. It opened at the downstairs Fitness Centre gym at 56–58 Crown House, Southwark Street, South London, a space Ramping hired because of its small, intimate size and affordability. The crowd in the first weeks was small enough that the Ramplings could greet each person as they arrived, and say goodnight as they left. Shoom's resident DJ Terry Farley believes this approach enhanced its early standing and helped develop its cult-like following. The local council had granted the gym an events licence, which meant that although they could not serve alcohol, they could stay open until 5 am, giving the nights an underground and illegal aura.

Rampling borrowed from family and friends to fund the opening night, and asked Carl Cox to provide the sound system. The gym had two rooms; Rampling and Cox played in the main hall, while Farley played funk and rare groove in the backroom. Although the opening night attracted around a hundred people and broke even, Danny did not view it as successful due to the unfocused variety of musical styles played. By the second night, his sets focused on Balearic and house music. He retained Cox as a regular DJ, but switched from Cox's sound system to one owned by DJ Joey Jay. Shoom almost immediately attained cult status with dance music fans, who saw it as the antithesis of the then-prevalent West End trend for clubs where it was "cool to be seen". Within weeks, the queue to enter the club grew from a few hundred to over a thousand, leading to a move in March 1988 to Thursday nights at Raw, a venue in the basement of a YMCA on Tottenham Court Road, and finally to Busby's venue on Charing Cross Road with even larger capacity.

The club's popularity grew after it was praised by influential clubbers such as Anton Le Pirate, Michael Clarke, Alan McGee and Bobby Gillespie, and celebrities including Sade, Leigh Bowery, Paul Rutherford, and the journalists Gary Crowley and Robert Elms. In each venue, Shoom was usually tightly packed with an above-capacity number of attendees. Writer David Cavanagh describes an atmosphere dominated by "heat and crush", while Richard Norris (later of the electronic dance group The Grid) said that when he attended, "there was no oxygen. We were lighting our lighters and the flames were going out." By January 1988, Shoom was using smiley face graphics in promotional flyers and posters. Widely used during the Summer of Love, Shoom re-popularised the image, leading to its eventual widespread use as an iconic emblem for the UK acid house movement.