Sean Lennon was born in New York City on October 9, 1975, his father's 35th birthday. He is of Irish and English descent on his father's side, and Japanese descent on his mother's side. Julian Lennon is his half-brother. Elton John is his godfather. After Sean's birth, John Lennon became a house husband, caring for his young son until his murder on December 8, 1980. Sean attended kindergarten in Tokyo and was educated at the exclusive private boarding school Institut Le Rosey in Rolle, Switzerland, and earlier at New York's private Ethical Culture Fieldston School and Dalton School. He attended Columbia University for three semesters before dropping out to focus on his music.
In January 1984, when Steve Jobs was visiting Manhattan, he attended a party that Sean's mother (Yoko Ono) was throwing for Lennon, and Jobs gave him one of the very first Macintosh computers.
His parents kick-started his musical career: his debut into the music world came at age five, when he recited a story on his mother's 1981 album, Season of Glass. From childhood into his teen years, Lennon continued to collaborate with his mother, contributing vocals and receiving production credit on her solo albums It's Alright, Starpeace and Onobox. At 16 Lennon co-wrote the song "All I Ever Wanted" with Lenny Kravitz for his 1991 album Mama Said. By 1995 Lennon had formed the band IMA (with Sam Koppelman and Timo Ellis) to play alongside his mother on her album Rising. Lennon also made appearances in film, featured in the cast of Michael Jackson's 1988 Moonwalker and portraying a teenager experiencing visions of various M. C. Escher prints in Sony's 1990 promotional short-film Infinite Escher.
Marianne Faithfull's album Easy Come, Easy Go (2008) – "Salvation" (originally by Black Rebel Motorcycle Club)
Salyu's compilation album Merkmal (2008) – "Shady"
Lennon contributed vocals and guitar to "Son Song", on the Soulfly album Primitive. He can be heard in the final seconds of the song talking about how Soulfly guitarist/vocalist Max Cavalera's heavy-gauge strings hurt his fingertips.
Deltron 3030's album Deltron 3030 (2000) – "Memory Loss"
Lennon sang backing vocals on the track "Sandpaperback" on Ben Lee's 1998 album Breathing Tornados.
Collaborated in John Zorn's Great Jewish Music tributes to Marc Bolan, Burt Bacharach and Serge Gainsbourg, in 1997 and 1998.
Lennon made a spoken-word contribution to The Flaming Lips' "Found This Star on the Ground", a six-hour song. Lennon read the names of charity contributors who had donated in order to have their names featured in the song.
Lennon was a featured artist on the track "Before the Skies" for Haale's EP Paratrooper.
Lennon covered "Row Bullies Row" with Charlotte Kemp Muhl and bassist Jack Shit for Son of Rogues Gallery: Pirate Ballads, Sea Songs & Chanteys (2013).
Lennon played slide guitar in Lady Gaga's "Sinner's Prayer", from her 2016 album Joanne.
Lennon appeared with The Sachal Ensemble on their album Song of Lahore (Universal, 2016)
Lennon was a featured artist on the track "Tomorrow Never Came", included on Lana Del Rey's 2017 album Lust for Life.
Lennon co-wrote "Theme for Valhalla Dale", from The Moonlandingz 2017 album, Interplanetary Class Classics.