Kozelek was born and raised in Massillon, Ohio. Upon relocating to Atlanta, Georgia, he met drummer Anthony Koutsos. After the pair moved once again to San Francisco, California, Red House Painters formed in 1989 with the addition of guitarist Gorden Mack and bassist Jerry Vessel. From 1992 to 1996, Red House Painters released a series of acclaimed albums, showcasing Kozelek's intense, highly autobiographical songs.
However, Kozelek's parting with the record label 4AD, followed by a major label merger which left Red House Painters' 1998 album Old Ramon on the shelf, proved highly frustrating and stifled the group's momentum. Kozelek opted to occupy himself with a series of idiosyncratic solo recordings as Red House Painters dissolved.
In 2000, he released the solo EP Rock 'n' Roll Singer, which featured three original songs as well as covers of John Denver's "Around and Around" and three AC/DC songs ("Rock 'n' Roll Singer," "Bad Boy Boogie," and "You Ain't Got a Hold on Me"). Two of the AC/DC cover versions on Rock 'n' Roll Singer were radical re-arrangements of the originals which removed the Bon Scott-penned lyrics from their hard rock context and placed them into gentle, acoustic "folk ballad" settings.
Kozelek expanded on this idea in 2001, releasing a full-length album comprised solely of AC/DC covers titled What's Next to the Moon.These new arrangements sounded so unlike the originals that a KCRW radio executive insisted that the title track was a Leonard Cohen song.
This was not the first time Kozelek had drastically re-arranged others' material to his own ends. With Red House Painters, he had previously done similar reconstructions with Simon & Garfunkel's "I Am a Rock," The Cars' "All Mixed Up," Yes's "Long Distance Runaround," Paul McCartney's "Silly Love Songs," and Francis Scott Key's "The Star-Spangled Banner."
In the years between his band projects, Kozelek's music made a number of appearances on compilations and tribute albums. He contributed the song "New Partner" to the Will Oldham (a.k.a. Bonnie 'Prince' Billy) tribute album, I Am Cold Rock. I Am Dull Grass Around this time, Kozelek commandeered a tribute album to John Denver, entitled Take Me Home: A Tribute to John Denver, featuring Will Oldham, The Innocence Mission, and Low to name a few. The compilation also featured Kozelek covering "Around and Around" as a duet with Rachel Goswell.
A limited edition live recording, White Christmas Live, was released by the Sub Pop label in late 2001. In addition to his solo material, it featured several Red House Painters songs done in a stripped-down, acoustic guitar-and-vocals style, and one a cappella rendition. An early version of his current project Sun Kil Moon's "Lily and Parrots" is tacked on to the end as an uncredited bonus track. It also features one previously unreleased song, "Admiral Fell Promises."
Sun Kil Moon debuted with Ghosts of the Great Highway in 2003, and also features former RHP members Jerry Vessel and Anthony Koutsos as well as new collaborators Geoff Stanfield (formerly of Black Lab) and Tim Mooney of American Music Club. Their follow-up effort appeared in 2005 on Kozelek's newly formed label, Caldo Verde Records. Titled Tiny Cities, the album is made up entirely of covers of songs by Modest Mouse. Once again, Kozelek's cover versions varied greatly from the originals.
In 2006, Kozelek was invited by Toronto indie rock label Paper Bag Records to exclusively contribute to their See You on the Moon! Songs for Kids of All Ages compilation with his original song "Leo and Luna." Then in November 2006, Kozelek released a live album titled Little Drummer Boy Live. On the album's two discs, he plays songs from his solo career, covers, and material from the catalogs of both Red House Painters and Sun Kil Moon.
Kozelek returned in 2008 with the release of Sun Kil Moon's third album April. The album features 11 brand new recordings, including guest vocal contributions by Ben Gibbard, Will Oldham, and Eric Pollard.
The release of the new album also brought the re-issue of Nights of Passed Over, a 256-page, hard-cover book of all the lyrics to Kozelek's solo songs, Red House Painters' songs, and Sun Kil Moon's songs. It also features setlists, handwritten lyrics, and a preface by Kozelek himself. The original edition of this book was released in 2002 in Portugal, and featured all the lyrics up to that point, printed in both English and Portuguese. The updated edition spans to his current Sun Kil Moon days, and the book also includes a 12-track bonus CD, titled Nights LP, featuring live and rare versions of songs dated 1996 to 2007. The edition is sold exclusively on his label's website link and is limited to 2,500 copies.
On December 9, 2008, Kozelek and Caldo Verde Records issued The Finally LP, a CD collection of 10 unreleased tracks, including covers of songs by Stephen Sondheim, Will Oldham, Hüsker Dü, and Low among others, as well as two previously unreleased instrumentals. Two newly-recorded live albums, Find Me, Ruben Olivares: Live in Spain and Lost Verses Live, followed in spring 2009.
On April 23, 2010, the release of Sun Kil Moon's fourth album, Admiral Fell Promises, was announced. The album was released on July 13, 2010.
A documentary film entitled Mark Kozelek: On Tour was released via Caldo Verde Records on August 16, 2011. The movie was filmed during portions Mark Kozelek's European/North American tours of 2010 and early 2011.
In 2012, an article at Queensberry-Rules.com by staff writer Mark Ortega detailed Kozelek's fascination with the sport of boxing, which inspired the name of his Sun Kil Moon project as well as a few songs on a Desertshore album.
“Their backgrounds are extremely harsh and they work very hard to move up in their careers. I was in attendance at the Manny Pacquiao-Agapito Sanchez fight in San Francisco in 2001. When I heard Sanchez was murdered shortly after, it had a profound effect on me. It hurts when anyone dies young, but when you see the backgrounds of these guys and the path they've taken to try to find some light in their lives, it hurts to see them die young.”