John Richard Deacon (born 19 August 1951) is an English retired musician who was the bass guitarist for the rock band Queen.

Deacon grew up in Oadby, Leicestershire, playing bass guitar in a local band, The Opposition, before moving to study electronics at Chelsea College, London.

After the death of lead singer Freddie Mercury in 1991 and the following year's Tribute Concert, Deacon performed only sporadically with the remaining members of Queen before retiring from the music industry in 1997 after recording "No-One but You (Only the Good Die Young)".

[7] Deacon took an interest in electronics at an early age, reading magazines on the subject and building small devices, including the modification of a reel-to-reel tape deck to record music directly from the radio.

[18] Although he left his bass and amplifier at home in Oadby, after less than a year of studying in London, Deacon decided he wanted to join a band.

[19] In 1970, Freddie Mercury, Brian May and Roger Taylor formed Queen; Deacon saw them in October that year but was not immediately impressed.

[17] Later in the year, he briefly formed a band called Deacon that made one live appearance at Chelsea College.

He wrote "Misfire", a Caribbean-themed song on which he played almost all guitar parts, and co-wrote "Stone Cold Crazy" with the rest of the band.

[28] His second song, written for his fiancée Veronica, "You're My Best Friend", was featured on the group's fourth album, A Night at the Opera (1975), and went on to be an international hit.

Subsequently, Deacon tended to write one or two songs for every Queen album, until The Miracle (1989) and Innuendo (1991), which credited the band as a whole.

[12] Deacon would collaborate with Mercury throughout the early 1980s, helping push the band's musical direction towards a lighter disco sound.

He performed on the single "Picking Up Sounds" by Man Friday & Jive Junior, a supergroup also featuring Thin Lizzy's Scott Gorham, Bad Company's Simon Kirke and Mick Ralphs, and The Pretenders' Martin Chambers[33][34] and played with The Immortals, which released the track "No Turning Back" as part of the soundtrack to the film Biggles: Adventures in Time.

[21] Deacon played bass on Mercury's single with Montserrat Caballe "How Can I Go On"[35] and also worked with Elton John and Hot Chocolate's Errol Brown.

"[21] After playing live with Queen three more times – at The Freddie Mercury Tribute Concert for AIDS Awareness on 20 April 1992, in a charity concert with Roger Taylor at Cowdray House in Midhurst on 18 September 1993, and at the opening of the Bejart Ballet in Paris on 17 January 1997, performing only "The Show Must Go On" with Elton John on lead vocals – he decided to retire from music.

[42] Deacon also appeared as a character in the parody biopic Weird: The Al Yankovic Story, played by David Dastmalchian.

[44] In a 2014 interview with Rolling Stone magazine regarding the forthcoming Queen + Adam Lambert North American tour with Adam Lambert, May and Taylor said that they no longer had much contact with Deacon except regarding finances, with Taylor stating that Deacon had "completely retired from any kind of social contact" and describing him as "a little fragile".

"[47] In 1973, Rolling Stone wrote that the combination of Taylor and Deacon "is explosive, a colossal sonic volcano whose eruption makes the earth tremble.

His most famous creation is the "Deacy Amp", built in 1972 from pieces of electronic equipment found in a skip, and used by himself and May throughout Queen's recording career.

[59] One of the reasons for Queen splitting from Trident, their original management company, is that it refused to lend Deacon money to put a deposit on a house.

[60][61] On 23 February 1985, Deacon was banned from driving for a year and fined £150 after being breathalysed for drink-driving in the West End of London.