Davis was the last member to join the band. James 'Munky' Shaffer and Brian 'Head' Welch discovered him in a bar, initially intending to only stay for a few minutes. Upon seeing Davis performing with his then-band Sexart, however, they were compelled to stay for the whole set, and as soon as the set was over Brian and James approached Davis with an offer to join their then band L.A.P.D.. At first he didn't accept the offer, but upon consulting a psychic, he agreed, and Korn was born. In early years, he was known for wearing a variety of normal and customized Adidas tracksuits onstage, which became a kind of "trademark" for all Korn fans.

Korn released their self-titled debut in 1994. It peaked at #72 on the billboard. To date they have released eight studio albums, achieving Platinum certification for each, with the exception for their newly released Untitled Korn album. Davis is the older half brother of former Adema and Midnight Panic vocalist, Mark Chavez.

Davis suffered from asthma as a child, having a near fatal attack at the age of 5 which hospitalized him. He noted in a 2004 interview that he was in and out of the hospital frequently as a child. His asthma has improved greatly and he's "...pretty much outgrown it."

Davis' earliest musical inspiration as a child was the Andrew Lloyd Webber musical "Jesus Christ Superstar". It was also during his childhood that he received his first drum kit and began his interest in music, eventually leading to a life-long passion and eventually a professional career as the lead singer of Korn. His favorite bands as a child were Duran Duran and other New Romantic bands.

Jonathan's personal issues are a big influence in Korn lyrics, songs such as "Daddy" from their self-titled album are a example how Davis puts all his anger and pain in the creation of songs. "Daddy" caused many to assume Rick Davis (Jonathan's father) had molested his son. It's a source of embarrassment for him, though his son has gone on the record in many interviews saying it was written about a family friend who sexually abused him. When a 12-year-old Jonathan tried to turn to his family, he said, they ignored him. (Neither Jonathan or Rick will say who the person was, though both say it was a woman.)

Davis has married twice, marrying his high school sweetheart, Renee Perez, in 1998 in a Medieval themed ceremony. Together they had a son, Nathan Houseman Davis, but were divorced in 2001. On October 5, 2004, a decade after the release of Korn's first album he married again in Hawaii, this time to former adult film actress Deven Davis. They were featured in the Playboy Cyber Club's "celebrity photographer" section, with Jonathan behind the camera and Deven modeling. In 2005 his second child, Pirate Houseman Davis, was born. Davis's third son, Zeppelin Houseman Davis, was born on April 28, 2007.

Davis has been sober from alcohol and other drugs since August 22, 1998. He has stated that he gave them up. On the band's Deuce DVD, former bandmate Brian Welch says that he is proud of him for becoming sober.

Jonathan has stated that Untouchables is his favorite Korn album and that "Do What They Say" and "Hollow Life" are his favorite Korn songs.

In late 2006, Davis was recognized and honored at Buck Owens' Crystal Palace, Bakersfield, CA, by Buddy Alan Owens, son of the late Buck Owens. Both Buck Owens and Davis are considered by many among their hometown fans as heroes to the sound of Bakersfield, each having their own pioneer sound, contributing to mainstream music worldwide over years past.

Davis has had a fairly small acting career. He has a cameo in Queen of the Damned as a ticket scalper. Davis plays as Ricky in the film Seeing Other People but his appearance is small, he plays a crackhead, and as a store clerk in the indie film The Still Life. Davis's most known acting role is in the upcoming horror film Sin-Jin Smyth where he will be playing the lead role. There is also a popular rumor that Davis will be in an upcoming horror/slasher film called Job but this has not been confirmed. According to Bloody-Disgusting, Jonathan Davis is currently working on a script with writer/director Clive Barker titled, "Oblivion" Davis describes it as a "dark opera about the end of the world" and that it's way different than Korn's style.

He has also been featured in many other bands' music videos, sometimes with Korn and sometimes without. He has appeared with Korn in Limp Bizkit's "Faith", Ice Cube's "Fuck Dying", and cameo appearances in Sugar Ray's "Answer The Phone". He has also appeared in Limp Bizkit's "Break Stuff", Videodrone's "TY Jonathan Down" (he is also featured in the song), Cold's "Give", and in Busta Rhymes's "Fire". In 2005 Davis and the rest of Korn appeared in an episode of the television comedy drama show Monk. The episode they appeared in was the season three episode Mr. Monk Gets Stuck in Traffic. As well as appearing in Monk, Davis and the rest of koRn guest starred on an episode of Comedy Central's "South Park" in an episode entitled "Korn's Groovy Pirate Ghost Mystery".

In Korn, Davis is usually seen with a microphone stand that was designed by the Swiss artist H. R. Giger on live performances and music videos . For his solo tour, Davis has not used the Giger stand.

In October 2007, Jonathan Davis announced he would be embarking on an acoustic solo tour called 'alone i play', his first ever, in November 2007. He has said he will be playing songs from the Queen Of The Damned soundtrack (which he co-composed), cover songs, rare unplayed Korn songs, and Korn classics. The tour is being completely produced by Richard Gibbs. His touring band consists of the following artists:

Michael Jochum - percussion
Shane Gibson - guitar
Miles Mosely - upright bass
Zac Baird - keyboards
Shenkar - violin

A DVD/CD of the tour is slated for a 2008 commercial release: Alone I Play CD/DVD.

Jonathan Davis has expressed interest in taking the solo tour to Europe. Once that concludes, he will release a solo studio album of the exact same band. They will be playing new original songs and covers for this upcoming release. On Kornspace, it was announced that JD is referring to his solo band as The Simply Fuckin' Amazings.