In addition to singing and playing both acoustic and electric guitar, Haynes also writes music. He spent his formative years in Asheville, North Carolina, where he lived with his two older brothers and his father, Edward Haynes. Warren began to play the guitar at age 12. His primary guitar is a Gibson Les Paul '58 Reissue Electric Guitar, his choice of a '58 is most likely because of Duane Allman's famed '58 Les Paul and the tone he achieved with that, rather than a more so commonly used '59 Les Paul model, popularized by guitarists such as Eric Clapton and Jimmy Page). Haynes has referred to himself as a "Gibson man", asides from Les Paul models he often plays Gibson Firebird and Gibson ES-335 models as well, this fact was acknowledged by American guitar maker Gibson who have incorporated a limited edition Warren Haynes signature Les Paul in its collection. Build according to Haynes' specifications and modeled on his '58 Les Paul.[1] Haynes is married to Stefani Scamardo, a DJ for Sirius radio and the long-time manager of Gov't Mule.

In 1993, Warren released his first solo album, Tales of Ordinary Madness, which was produced by former Allman Brother keyboardist Chuck Leavell. He toured briefly in support of the record with various musicians.

In 2003 and 2004, Warren released two solo acoustic albums, The Lone EP, a collection of live performances and Live From Bonnaroo which documents his solo performance at the 2003 Bonnaroo Music Festival. When not touring with one of his electric bands, Warren will often take time out to do solo acoustic shows which include a variety of well-known and rare covers along with his own material. In 2004, Warren Haynes performed five full-length solo acoustic shows, as well as opened 23 times for The Dead and once for The Allman Brothers Band.

He has also made 45 song appearances and 28 concert appearances with Dave Matthews Band, including on two released live albums: Live at Central Park Concert in which he performed "Cortez the Killer", and "Jimi Thing", and Live at Piedmont Park where he performed "What Would You Say".

In 2005 Warren performed a one time only show under the name Warren Haynes & Friends. The band included Abts on drums, Dave Schools of Widespread Panic on bass, John Medeski of Medeski Martin & Wood, and Skerik the avant-garde sax player of bands such as Critters Buggin' and Les Claypool's Fearless Flying Frog Brigade. The group played a selection of blues songs, including songs of Led Zeppelin, Jimi Hendrix, Tom Waits, and Gov't Mule standards. The band was also featured as the house band during a number of tapings of Carson Daly's late show in early February 2005. During one of these tapings, the scheduled musical act was absent, so Warren performed an acoustic rendition of U2's One. The song also appeared on his Live from Bonnaroo album.

After recording Gov't Mule's By a Thread album, Warren put together a group of musicians to be known as The Warren Haynes Band. The core of the group includes George Porter Jr. on bass, Ivan Neville on keys and Raymond Weber on drums. Also joining them on keys is Ian McLagan, as well as vocalist Ruthie Foster and Ron Holloway on tenor sax. The Warren Haynes Band made their debut performance at Haynes' annual Christmas Jam in Asheville, North Carolina on December 11, 2010.[3] The album, Man in Motion, was released in May 2011.