Guy Levy was born in 1975 in Mevaseret Zion, just outside Jerusalem, and started on double bass as a teenager at the Rene Cassin High School in Jerusalem. He trained formally at the Jerusalem Academy of Music and Dance from 1997 to 1999, then continued at the Conservatorium van Amsterdam (the Royal Conservatory) from 1999 to 2001, studying classical bass under Peter Stotijn and Matthew McDonald alongside jazz under Arnie Lawrence, the American saxophonist and jazz educator who later founded Jerusalem's own International Center for Creative Music.

Levy's early professional years, roughly 2005 to 2009, ran on two tracks at once: as principal double bassist with the Jerusalem Symphony Orchestra on the classical side, and as a working jazz bassist on the other, including a stretch in Berlin's jazz scene and sideman dates alongside American saxophonist Abraham Burton and vocalist Sheila Jordan.

That jazz work produced his debut as a leader: Tel Aviv (2013), a trio session with pianist Uri Gincel and drummer Felix Astor, all original compositions, recorded live in Berlin over a single winter session. The same year, he also contributed to Pen - New Music for Alexander Pen's Songs, an ACUM-backed project setting the Hebrew poet Alexander Pen's texts to new music.

From roughly 2010 on, Levy built a second, much larger career in composition and production alongside his bass playing. He wrote string arrangements for the rock act Mercedes Band (Zehut, 2011), scored the Israeli television series Ori and Ella (2016, with Gal Toren), On the Spectrum (2018, with Tal Aven Tzur), the first season of Stockholm (2018), the children's series Cafe Amalia (2020-present), and Rehearsals (2021, a series later sold to Hulu), and scored the theater production There Was Peace, Mr. Hoffman (2022). With Toren, he also co-writes and produces the indie-pop duo Layli, whose self-titled debut appeared on Nana Disc in 2017 with a follow-up in 2022. In 2017 he released Songs for Amalia, a children's album made with pianist Tal Aven Tzur, featuring vocalists Alma Zack and Alon Neumann. He also had a decade-long production and performing relationship with singer Efrat Ben Tzur, from 2012 to 2022.

Levy returned to leading a jazz group in 2024 with Guy Levy Sextet: Tel Aviv Session (NaNa Disc), a seven-track, 55-minute session featuring saxophonist Asaf Yuria, trombonist Jonathan Voltzok (credited here as Yonatan Voltzok), Amit Friedman, Katia Toobool, and Yonatan Rosen. He continues to teach double bass at Ben Tzvi High School in Kiryat Ono, the Raanana Conservatory, and the Israeli Conservatory of Music in Tel Aviv, and is described on the Israeli jazz-club portal Hot Jazz as a "versatile musician proficient in classical, rock, pop, jazz and world music," with additional jazz-circuit ties to Yuval Cohen, Yonatan Albalak, and bassist Yoav Asher.

Levy's jazz identity rests on real, verifiable foundations: a conservatory-level bass education spanning classical and jazz study under Arnie Lawrence in Amsterdam, early-career work alongside American jazz names Abraham Burton and Sheila Jordan, and two acoustic jazz albums as a leader eleven years apart, Tel Aviv (2013) and Guy Levy Sextet: Tel Aviv Session (2024), both original-composition sessions in a straight-ahead, post-bop idiom. At the same time, most of his working career since around 2010 sits outside jazz: television and theater scoring, a children's music catalog, string arrangements for a rock band, and Layli, an ongoing indie-pop project with Gal Toren. This is a genuinely mixed career rather than a purely jazz one, and it is stated here plainly rather than smoothed over: Levy is a trained, active jazz bassist who also earns most of his living from screen composition and pop production.