In 2007, he founded The White Feather Foundation (TWFF), whose stated mission goal is to address "environmental and humanitarian issues".

[5] When Julian was five years old, in 1968, his parents divorced, following his father's infidelity with Japanese multimedia artist Yoko Ono.

John Lennon bought Julian a Gibson Les Paul guitar and a drum machine for Christmas 1973 and encouraged his interest in music by showing him some chords.

[11][12] Following his father's murder on 8 December 1980, Julian Lennon voiced anger and resentment toward him, saying, "I've never really wanted to know the truth about how Dad was with me.

Dad could talk about peace and love out loud to the world but he could never show it to the people who supposedly meant the most to him: his wife and son.

Julian sued his father's estate and in 1996 reached a settlement agreement, authorised by Lennon's widow, Yoko Ono, reportedly worth £20 million.

[18][19][20] In an interview with CBS News in 2009, Julian stated, "I realised if I continued to feel that anger and bitterness towards my dad, I would have a constant cloud hanging over my head my whole life.

After recording the song 'Lucy,' almost by nature, it felt right to fulfill the circle, forgive Dad, put the pain, anger and bitterness in the past, and focus and appreciate the good things.

"[24] In the sleeve notes in the album the song is credited to Julian Lennon "starring on drums" with "dad on piano".

Produced by Phil Ramone, it spawned two top 10 hits, (the title track and "Too Late for Goodbyes") and earned Lennon a nomination for the Grammy Award for Best New Artist in 1986.

Music videos for the two hits were made by film director Sam Peckinpah and producer Martin Lewis.

On 1 April 1987, Julian Lennon appeared as the Baker in Mike Batt's musical The Hunting of the Snark (based on Lewis Carroll's poem).

[27] The all-star lineup included Roger Daltrey, Justin Hayward and Billy Connolly, with John Hurt as the narrator.

The performance, a musical benefit at London's Royal Albert Hall in aid of the deaf, was attended by the Duchess of York.

During this time, Lennon contributed a cover of the Rolling Stones' "Ruby Tuesday" to the soundtrack of the television series The Wonder Years.

[30] Lennon left the music business for several years in the 1990s to focus on philanthropy after his encounter with elders from the Mirning people of Australia.

In 2012 he worked with music film director Dick Carruthers on the feature-length video documentary Through the Picture Window, which followed Lennon's journey in the making of Everything Changes and includes interviews with Steven Tyler, Bono, Gregory Darling, Mark Spiro and Paul Buchanan from The Blue Nile.

"[44] The title is a reference to the Beatles song "Hey Jude", which Paul McCartney wrote in 1968 to give Julian Lennon hope for the future.

[44][45] Lennon said about his album title, "Calling it Jude was very coming of age for me in that regard because it was very much facing up to who I am...The content came from over three decades of songwriting.

Lennon is also the producer of the documentary, Whaledreamers, about an Indigenous Australian tribe and the peoples' special connection with whales.

[2][52] In 2020, Lennon was an executive producer of Kiss the Ground, an award-winning documentary film about regenerative agriculture, narrated by Woody Harrelson.

[54] Lennon's "Alone" collection was featured at the Art Basel Miami Beach Show from 6–9 December 2012, to raise money for The White Feather Foundation.

[62] In 2023, Lennon showed a series of photographs in an exhibition titled ATMOSPHERIA at William Turner Gallery in Santa Monica, California.

[68] On 9 November 2021, Lennon published a graphic novel for middle-grade children, The Morning Tribe, with co-author Bart Davis.

[69][70] A conversation Lennon once had with his father went as follows: "Dad once said to me that should he pass away, if there was some way of letting me know he was going to be OK – that we were all going to be OK – the message would come to me in the form of a white feather.

[74] In response, he produced the documentary Whaledreamers about their tribe, and in 2007 he founded The White Feather Foundation (TWFF),[75][76] whose mission "embraces environmental and humanitarian issues and in conjunction with partners from around the world helps to raise funds for the betterment of all life, and to honor those who have truly made a difference.

"[77] TWFF partners with philanthropists and charities around the world to raise funds for various humanitarian projects in four major areas of giving: clean water, the preservation of Indigenous cultures, the environment and education and health.

In 2019, Lennon contributed his voice and music to the soundtrack of narrative feature film One Little Finger, which has the initiative to spread awareness about 'ability in disability'.

[90] After living with his parents at Kenwood in Weybridge outside London from 1964 to 1968, Lennon moved with his mother to a number of British locales, eventually settling in The Wirral near Liverpool and then to a farm in North Wales.