He is well known for his bass playing on songs such as "Gloria", "New Year's Day", "Bullet the Blue Sky", "With or Without You", "Mysterious Ways", "Vertigo", "Get On Your Boots", and "Magnificent".

[4] When he was eight years old, Clayton was sent to the private junior boarding Castle Park School in Dalkey, southern County Dublin.

Here he made friends with other pupils who were enthusiastic about the pop/rock music acts of the period, including the Who, the Beatles, Grateful Dead, and Carole King.

In response, he bought a £5 acoustic guitar from a junk shop near the Dublin quays, and began learning elementary chords and songs.

[8] In September 1976, Mullen put an advert onto the school's bulletin board seeking other musicians to form a band; Clayton showed up for the first meeting and practice, as did the Edge with his older brother Richard Evans ("Dik"), Bono, and Mullen's friends Ivan McCormick and Peter Martin, who both left the band soon after its inception.

[9] Clayton stood in as the nearest thing that the band had to a manager in its early life, handing over the duties to Paul McGuinness in May 1978.

Prior to this Clayton had only provided live backing vocals to tracks such as "Out of Control", "I Will Follow", "Twilight", and "Bullet the Blue Sky".

[14] Clayton played on Sharon Shannon's song "The Marguerita Suite" from her self-titled debut album, which was released in October 1991.

[15] In 1994, Clayton played bass alongside Mullen on Nanci Griffith's album Flyer, appearing on the songs "These Days in an Open Book", "Don't Forget About Me", "On Grafton Street" and "This Heart".

Clayton's style of bass guitar playing is noted for what instructor Patrick Pfeiffer called "harmonic syncopation".

With this technique, Clayton plays a consistent rhythm that stresses the eighth note of each bar, but he "anticipates the harmony by shifting the tonality" before the guitar chords do.

"[21] In the band's early years, Clayton generally played simple bass parts in 44 time consisting of steady eighth notes emphasising the roots of chords.

[22] Author Bill Flanagan said that he "often plays with the swollen, vibrating bottom sound of a Jamaican dub bassist, covering the most sonic space with the smallest number of notes".

[24] He cites bassists such as Paul Simonon, Bruce Foxton, Peter Hook, Jean-Jacques Burnel,[22] and James Jamerson as major influences on him.

[22] One of Clayton's most recognisable basslines is from "New Year's Day", which was borne out of an attempt to play Visage's song "Fade to Grey".

Clayton also sang backup vocals on "I Will Follow", "Twilight", "Trip Through Your Wires" and also on some occasions on "With or Without You" and "Bullet the Blue Sky" during live performances.

Clayton's first bass was a walnut brown Ibanez Musician, which he played heavily from the recording of Boy and well through the War era.

[22] In 2011, the Fender Custom Shop produced a limited-edition signature Precision Bass built to Clayton's own specifications in a limited run of 60 pieces, featuring an alder body and a gold sparkle finish.

On 26 November 1993, he was so hung over that he was unable to play that night's show in Sydney, the dress rehearsal for their Zoo TV concert film.

[40][41] On 26 June 2017, Clayton received the Stevie Ray Vaughan Award at the MusiCares 13th annual MAP Fund Benefit Concert in recognition of his commitment to helping others with addiction recovery.

[45] The Independent reported in 2015 that de Carvalho, originally from Brazil, works as a director at Michael Werner, a leading contemporary art gallery in London and New York.

[47] In 2009 the High Court ordered the assets of Carol Hawkins, Clayton's former housekeeper and personal assistant, be frozen after it was reported that she misappropriated funds of €1.8 million.

[51] In April 2024, Clayton was featured in an episode of BBC's Gardeners' World, showing his collection of camellia, magnolia and rhododendron at his Dublin home, to interviewer Adam Frost.

[52] Clayton will also be a presenter on the television programme Ballroom Blitz, which was commissioned by RTÉ and will explore the history of Irish showbands.