Yussef Dayes was born in South London on December 12, 1992, the youngest of four brothers. His mother, from Somerset, worked as a primary school teacher and yoga instructor; his father, of Jamaican Rastafarian descent, was a merchant who played bass guitar. His father gave him a first drum kit when he was four, and he began performing with his brothers, who had all been taught piano. At ten he attended a course taught by the drummer Billy Cobham. He has described a mixed diet of influences: his father's jazz and reggae records, his mother's country and Beatles records, his brother Ahmad's jungle productions, and the grime and hip-hop he heard growing up.

His first serious band was United Vibrations, formed around 2009 with his brothers Ahmad (trombone) and Kareem (bass) and the saxophonist Wayne Francis II, playing what one account calls Afrobeat stylings alongside forward-looking jazz and rock. The group's first single, "Ra!", appeared in 2009, they toured the UK as Aloe Blacc's backing band and played on Later... with Jools Holland, and they released the album Galaxies Not Ghettos (2011), the EP We Never Die (2012) and the album The Myth of the Golden Ratio (2016). He also played drums on Two For Joy (22a, 2015), an album by the Tenderlonious-led jazz band Ruby Rushton.

The breakthrough was Yussef Kamaal, a duo with the keyboardist Kamaal Williams, who had first booked United Vibrations for an event he was promoting. After rehearsing Williams's solo material for a Boiler Room session, the two began playing as a band. A 20-minute set at Gilles Peterson's Worldwide Awards in 2016 led to a deal with Peterson's Brownswood Recordings, which released their only studio album, Black Focus, on November 4, 2016. It was recorded at Quartermass Studios with Malcolm Catto among its producers, and the personnel added the saxophonist Shabaka Hutchings, the trumpeter Yelfris Valdes, the bassists Tom Driessler and Kareem Dayes and the guitarist Mansur Brown. Dayes and Williams are both credited as writers, performers and producers. The duo won the Breakthrough Award at the 2017 Jazz FM Awards, but in March 2017, shortly before a scheduled SXSW appearance, Dayes's visa was revoked under a US immigration order and the group was refused entry. In May 2017 they announced that the original line-up would no longer perform together.

Dayes then used his own label, Cashmere Thoughts, to release "Love Is the Message" (July 2018) and "Blacked Out" (September 2018) with the keyboardist Alfa Mist, the first with the guitarist Mansur Brown, followed by a live version of "Love Is the Message" recorded at Abbey Road Studios with Brown and the bassist Rocco Palladino. His working trio of Dayes, Palladino and the keyboardist Charlie Stacey became the core of his live band, and a live album, Welcome to the Hills, appeared on Cashmere Thoughts in December 2020. It draws on 2018 and 2019 shows, including a set in Copenhagen on July 9, 2019, and includes an extended reading of Stanley Clarke's "Yesterday Princess."

Between those releases came the collaboration with the guitarist and singer Tom Misch. The two met at the launch party for Misch's 2018 album Geography, recorded What Kinda Music in a series of jam sessions, some of them fully improvised, and released it on April 24, 2020 through Misch's Beyond the Groove label with Blue Note Records and Caroline. It reached number 4 on the UK Albums Chart, Dayes's first chart appearance, and was nominated for the Best Album Ivor Novello Award in 2021.

His own band, the Yussef Dayes Experience, with Palladino, the keyboardist Elijah Fox, the saxophonist Malik Venner (Venna) and the percussionist Alexander Bourt, released the EP Live at Joshua Tree (Presented by Soulection) in 2022. His debut solo studio album, Black Classical Music, followed on September 8, 2023, through Brownswood, Warner Music and Cashmere Thoughts, and through Nonesuch Records in the United States. It runs to 19 tracks, with guests including Shabaka Hutchings, Tom Misch, the reggae singer Chronixx, the singer and multi-instrumentalist Masego, Jahaan Sweet, Leon Thomas and the Chineke! Orchestra, and it ends with a recording of his late mother, Barbara Hicks, who died in 2015. At the 2024 Ivor Novello Awards on May 23, 2024, it won Best Album, credited to Dayes, Palladino and Stacey; the judges praised its narrative arc and its modern reframing of instrumental music. He was also a nominee for Best New Artist at the 2024 Brit Awards, and a co-writer of Sampha's "Spirit 2.0" (on which he plays drums), which was nominated for the Ivors' Best Song Musically and Lyrically.

A run of live and collaborative records followed. The Yussef Dayes Experience (Live From Malibu) came out on January 26, 2024. He played drums on two tracks of Sampha's Lahai (2023), on "Blue" from Kali Uchis's Red Moon in Venus (2023) and on the title track of Little Simz's Lotus (2025), a track that also features Michael Kiwanuka. In 2025 he released a live album with the French producer FKJ, Live From the Greenhouse. After filming a live set at Mount Fuji with the Japanese vocalist and sanshin player Minami Kizuki, the band issued Mt. Fuji FM, a vinyl set with commentary from Gilles Peterson, in December 2025, followed by the music-only Live From Mt. Fuji on March 6, 2026. The single "Chi Ave / A Love Letter to Salvador," from that set, was released on May 15, 2026.

Dayes plays a busy, melodic, highly articulate kit that draws as much on jungle breakbeats, grime and hip-hop as on the jazz-funk of the 1970s, and he is open about that mix. His records combine broken beat and UK club rhythms, soul and R&B vocals, reggae and Afrobeat grooves, and electronic production and synthesizers, all arranged around live drums. AllMusic's Thom Jurek heard Black Focus as a weave of spiritual jazz-funk, broken beat and global sounds, built on the jungle, UK garage, grime, hip-hop and post-Joe Harriott British jazz its makers grew up on. What Kinda Music blurs acid jazz, psychedelia, hip-hop and electronica, with Dayes as the more experimental, jazz-minded half of the pairing. A review of Black Classical Music in Uncut listed West Coast fusion, Herbie Hancock-style funk and psychedelic soul-jazz among its reference points. Much of this music is groove-led and studio-shaped rather than built on long improvised solos, and a great deal of his public profile rests on collaborations with pop, R&B and hip-hop artists such as Tom Misch, Masego, Sampha and Kali Uchis.

The jazz-side credentials are real and specific. Wikipedia introduces him as an English jazz drummer, composer and record producer, his career took off in the South London scene around Gilles Peterson and Brownswood, and he attended a course by Billy Cobham as a child. What Kinda Music was released through Blue Note, Black Classical Music won the Ivor Novello for Best Album, he has taken on Stanley Clarke's repertoire live, and in announcing the album he described the "Black Classical Music" of its title as a continuing lineage running through Miles Davis, Rahsaan Roland Kirk, Nina Simone, John Coltrane and Louis Armstrong. He has described the aim of Black Focus as keeping the core jazz principles of spontaneity and flow, and the live records with his trio and with the Experience are where that improvising shows most plainly.