Grey grew up in a small town 40 miles south of Jacksonville, Florida, and when he was young he developed a passion for surfing. While Grey enjoyed several years wandering the world's beaches as a surf bum, his love of music brought him back home and he began honing his skills as a guitarist and writing songs.

While working a day job fixing air conditioners, Grey met Daryl Hance, a co-worker who played guitar. Grey wanted to start a band and he teamed up with Hance to form JJ Grey & Mofro, who earned a loyal following in the South for their gritty swamp rock. In 1994, a record company in Great Britain heard Grey's demo and offered Mofro a record deal; the band flew to the U.K. for recording sessions, but the deal fell through at the last minute, and Grey and Hance assembled a new version of Mofro with English musicians in hopes of landing another contract.

Ironically, Grey's search for a new record deal brought him back to the United States when his music came to the attention of Dan Prothero, a producer and engineer who ran the San Francisco-based independent label Fog City Records. Prothero liked Grey and Mofro's music, and both produced and released their 2001 debut album Blackwater. A second album with Fog City, Lochloosa, appeared in 2004, and Grey and Mofro developed a growing nationwide fan base through constant touring and positive word of mouth, playing coveted spots on the festival circuit (including Bonnaroo, the Austin City Limits Festival, and the New Orleans Jazz and Heritage Festival) and opening for everyone from Jeff Beck to Ben Harper.

In 2006, Grey signed a deal with the venerable blues label Alligator Records, and with Prothero once again behind the controls, Grey and Mofro cut their third album, Country Ghetto, which was released in early 2007, and the critically acclaimed Orange Blossoms appeared in 2008. In 2010, Grey and Mofro issued Georgia Warhorse, their third album for Alligator; the set featured guest appearances from Derek Trucks and Toots Hibbert. Grey and Mofro received almost universal critical acclaim for the album and their road show, as they toured throughout the remainder of 2010 and 2011. In the fall of that year, they issued the live DVD/CD document Brighter Days on Alligator. Recorded at Atlanta's Variety Playhouse in January 2011, the film was directed by Spookie Daly; it interspersed live footage and band interviews with commentary from Grey and others. A new studio album, This River, followed in April of 2013.

Grey decided on a different approach for the band's next recording. Instead of presenting the musicians with demos of the songs beforehand, he went in with the charts in his head, then vaguely described what he wanted; it created a more equitable and balanced feel among the players studio. The resulting album, Ol' Glory, was released in February of 2015 on Provogue. ~ Mark Deming