After being raised by both his parents in Montclair, New Jersey and his grandparents in Hilton Head, South Carolina (of whom his Juilliard-trained grandmother taught him piano), and after graduating from Phillips Academy, Andover in 1988, Sheik studied semiotics at Brown University, and moved to Los Angeles. Playing for other artists, including Liz and Lisa (with Lisa Loeb and Elizabeth Mitchell), Sheik also played on His Boy Elroy's 1993 album through his connections from fellow Brown alum, Tracee Ellis Ross. He is the half brother of Broadway actress Kacie Sheik.
In 1996, Sheik released his self-titled debut album, which was certified Gold and spawned the #16 peaking hit single, "Barely Breathing", which itself remained on the Billboard Hot 100 for a record-setting 55 consecutive weeks. The popular track also enjoyed Top 20 success on Adult Contemporary radio and topped the Adult Top 40 charts. The song garnered a Grammy Award nomination for Best Male Pop Vocal Performance.
In 1998, Sheik released Humming, an experimental follow-up with string arrangements.
In 2001, Sheik released Phantom Moon, a Nick Drake-influenced album which was a collaboration with poet and writer Steven Sater.
In 2002, Sheik released Daylight, a brighter, more modern-sounding album which included the singles, "On A High" and "Half-Life".
In 2002, Sheik composed original music for the New York Shakespeare Festival production, Twelfth Night.
In 2004, Sheik composed the score for A Home at the End of the World, and, later, composed the score for Through the Fire.
In 2006, Sheik released White Limousine, an album which included companion software on a DVD-ROM to remix individual tracks.
In 2006, Sheik wrote the music for Spring Awakening, another collaboration with Sater. Written over a period of eight years, the musical, which premiered off-Broadway in New York during the summer, opened on Broadway to critical acclaim later in the fall. Based on the controversial German expressionist play, The Awakening of Spring by Frank Wedekind, the musical won Tony Awards for "Best Orchestration" and "Best Original Score" (Music), as well as "Best Musical". The original cast recording album received the Grammy Award in 2008 for "Best Musical Show Album", and the guitar that Sheik used to compose songs for the Spring Awakening is currently on display at the New York Public Library for the Performing Arts at Lincoln Center.
In 2008, Sheik was a judge at the 7th annual Independent Music Awards.
In 2009, Sheik released Whisper House, a concept album which provided the score for the musical of the same name.
In 2011, Sheik released Covers 80's, which included covers of popular 1980s songs. Concert dates in support of the album were later canceled due to Sheik seeking treatment for alcohol addiction. In a message to fans in his tumblr blog, Sheik noted that he had entered a treatment center on the same day his latest album was released and had told his staff, "My record is coming out and I’m checking in." A remixed version of the album was released the following year.
In 2012, Sheik wrote Alice By Heart, an adaptation of Lewis Carroll's Alice's Adventures in Wonderland, along with collaborator Sater. Directed by Jessie Nelson with musical direction by Lance Horne, the musical was workshopped at the Royal National Theatre and commissioned by the National Theatre Connections.
In 2013, Sheik wrote the music and lyrics to the musical adaptation of American Psycho, which opened at the Almeida Theatre in London, and was later staged on Broadway in 2016. That same year, Sheik wrote the music for the musical adaptation of the novel Because of Winn-Dixie, which opened at the Arkansas Repertory Theatre. Dixie was a collaboration with director John Tartaglia and Nell Benjamin, who wrote the book and lyrics. The star is an Irish wolfhound trained and provided by William Berloni Theatrical Animals, Inc. If the show moves to Broadway, it will be the first play with a dog as the lead.
In 2015, Sheik wrote the musical thriller Noir along with collaborator Kyle Jarrow, which premiered as part of New York Stage and Film's Powerhouse season. Inspired by live radio plays and classic film noir, the musical was directed by Rachel Chavkin. In addition, Sheik released a new studio album, titled Legerdemain, in October of this year.
Currently, Sheik is composing the music for a feature-film adaptation of Spring Awakening, an adaptation almost a decade in the making.At the Reservoir EP (1997, Atlantic)
Humming Along EP (1998, Atlantic)
White Limousine EP (2005, Zoë)
Brighter/Later: A Duncan Sheik Anthology (2006, Rhino)
Brighter: A Duncan Sheik Collection (2007, Rhino)
On Stage at World Café Live: Duncan Sheik DVD (2007)
Whisper House EP (2008)
80s Covers EP (2010, Sneaky Records Inc.)
Music from the Motion Picture 'Harvest' EP (w/ David Poe) (2011)
Twelfth Night - 2002
Nero (Another Golden Rome) - 2006
Spring Awakening - 2006, 2007—2009
The Nightingale - 2006 (based on The Nightingale)
Whisper House - 2010
Carson McCullers Talks About Love (with Suzanne Vega) - 2011
Alice by Heart - 2012
American Psycho - 2013
"The Taming of the Shrew - 2016
In 1998, Sheik recorded "Embraceable You" for Red Hot + Rhapsody, a George Gershwin tribute to increase AIDS awareness, and also recorded "Songbird" for another tribute, Legacy: A Tribute to Fleetwood Mac's Rumours.
In 1999, Sheik produced singer/songwriter Micah Green's debut album, as well as his 2012 follow-up.
In 2000, Sheik wrote the foreword to The Way of Youth: Buddhist Common Sense for Handling Life's Questions, by Soka Gakkai International leader Daisaku Ikeda.
In 2000, Sheik sang a duet with singer Howard Jones on Jones' single Someone You Need.
In 2006, Sheik recorded the song, "A Purple Trail", for Other Songs and Dances, Vol. 1.
In 2008, Sheik participated in Songs for Tibet: The Art of Peace, an initiative to support Tibet, Dalai Lama and Tenzin Gyatso.