In 1978, at the age of 9, Harper attended Bob Marley’s performance in Burbank, California where Marley was joined by former bandmate Peter Tosh for the encore. It was, according to Harper, an important influence.

At the age of 12, Harper played his first gig. During the 1980s, in his teen years, Harper began to play the slide guitar, mimicking the style of Robert Johnson. Harper refined his style, taking up the Weissenborn slide guitar. Harper broke out of the Inland Empire after being offered an invitation by Taj Mahal to tour with the artist. They recorded Taj Mahal’s album Follow the Drinking Gourd, released in November 1990, and toured Hawaii.

In 1992, Harper recorded the LP Pleasure and Pain with folk multi-instrumentalist Tom Freund. After this limited edition record, Harper secured a lifetime record deal with Virgin Records, which released his debut album, Welcome to the Cruel World in 1994. This allowed him to be invited at the Rencontres Trans Musicales of Rennes in France in December 1993 where he went up for the first time on a large stage.

The first album was followed by Fight For Your Mind in 1995, with Juan Nelson on bass, which became a college radio favorite and included several songs that Harper still plays live regularly.

In 1996, Harper married his first wife, Joanna. They have two children together, son Charles (born circa 1997) and daughter Harris (born circa 2000). Harper and Joanna separated in 2000, and were divorced in 2001.

In 1999, at the Santa Barbara Bowl, Harper met Jack Johnson and sent a demo tape of Johnson’s songs to his producer, J. P. Plunier, who then produced Johnson’s first album, Brushfire Fairytales, in December 2000. Jack Johnson became the opening act in late February 2001 for the last twenty-three cities of Ben Harper’s “Innocent Criminals” tour of the United States.

Harper began dating actress Laura Dern after they met at one of his concerts in fall 2000. Harper and Dern married on December 23, 2005 at their home in Los Angeles. They have two children, son Ellery Walker (born August 2001) and daughter Jaya (born November 2004).

In 2002, Harper was one of the featured singers covering Motown hits by Marvin Gaye in the documentary, Standing in the Shadows of Motown (a history of The Funk Brothers). Harper was featured on the album True Love by Toots and the Maytals, which won the Grammy Award in 2004 for Best Reggae Album, and showcased many notable musicians including Willie Nelson, Eric Clapton, Jeff Beck, Trey Anastasio, Gwen Stefani / No Doubt, Bonnie Raitt, Manu Chao, The Roots, Ryan Adams, Keith Richards, Toots Hibbert, Paul Douglas, Jackie Jackson, Ken Boothe, and The Skatalites.

Early in Harper’s career, his music received more attention in Europe and was widely played in Australia (first on Triple J radio). Harper has made comments on a number of occasions that his career was kicked off in Australia. While he was a well-known and respected figure in the United States, he was also a star in countries like Australia, New Zealand, France, Portugal, Germany, Switzerland and the Netherlands, receiving a great deal of airplay and critical acclaim. His popularity in Europe became wide enough that he was French Rolling Stone magazine’s Artist of the Year (Artiste De L’Année) in 2003, and his Australian tour that year for Diamonds on the Inside was highly successful with record sales.

On April 3, 2004, Harper and Jack Johnson performed with Toots and the Maytals on Saturday Night Live (season 29, episode 16), a show hosted by Donald Trump.

In October 2004, Harper participated in the Vote for Change concert tour organized to benefit Moveon.org and encourage people in the swing states to vote during the 2004 U.S. presidential election. In the same month, Harper contributed a live recording of the song “Oppression” to For The Lady, a benefit album for jailed Nobel Peace Prize winner and Burmese pro-democracy advocate Aung San Suu Kyi.

In 2006, Harper released the double album Both Sides of the Gun which debuted at #7 on the Billboard charts. Though uncredited, he appears briefly in the 2006 David Lynch film Inland Empire, alongside his wife Laura Dern.

Harper is part of the No Nukes group which is against the expansion of nuclear power. In 2007 the group recorded a music video of a new version of the Buffalo Springfield song “For What It’s Worth”. Harper’s collaboration “Boa Sorte/Good Luck” with Brazilian singer Vanessa da Mata peaked at #1 in Brazil and Portugal. In Brazil it also won a highly coveted Prêmio Multishow for “Best Song” in 2008. Also in 2008, Harper participated in the benefit album Songs for Tibet.

On August 27, 2010, it was reported that Harper had formed a band called Fistful of Mercy with Dhani Harrison and Joseph Arthur. Fistful of Mercy released their debut record, As I Call You Down, on October 5, 2010.

In October 2010, Harper filed for divorce from Dern, citing irreconcilable differences. They briefly reconciled and attended the 2012 Golden Globe Awards together, but Dern reactivated the divorce by filing a legal response in July 2012. The divorce was finalized in September 2013.

On May 17, 2011, Harper’s official site posted that his next album was released, entitled Give Till It’s Gone. The album is a continuation of recording with Relentless7.

On October 1, 2012, a new album from Harper with Charlie Musselwhite was announced entitled Get Up! on Stax Records / Concord Music Group. The official release date for the album was January 29, 2013. Get Up! was recorded in Los Angeles and produced by Harper. It is Harper’s 12th studio album and first new recording since 2011’s Give Till It’s Gone (Virgin).

In December 2012, it was announced that Harper had co-produced lead vocalist Natalie Maines of the Dixie Chicks first solo rock album Mother. It was released on May 7, 2013.

Harper supports Little Kids Rock, a national nonprofit organization that works to restore and revitalize music education in disadvantaged U.S. public schools. In 2013, he donated items to their San Francisco Bay Area benefit concert.

In early 2015, it was announced that Harper and The Innocent Criminals would perform at the Boston Calling Music Festival in May 2015. Ben Harper and The Innocent Criminals performed at Rock Werchter Festival 2015 on June 28, 2015 .

Harper married his third wife, social advocate Jaclyn Matfus, on January 1, 2015. Their son Besso was born in June 2017.

On 12 February 2016, Harper released (as a YouTube video) his new single “Call It What It Is”, first track taken from his upcoming new studio album Call It What It Is due to be released on 8 April 2016.

Harper is a skateboarder who has trained with Rodney Mullen and he also owns a warehouse for his personal skateboarding. Harper co-owns the skateboarding brand Roller Horror with professional skateboarder Mike York. In September 2016, Harper appeared on The Nine Club skateboard podcast, hosted by Chris Roberts, where he discussed his relationship and history with skateboarding. On The Nine Club, he also reveals that he went to school and began skateboarding with Chris Miller in Pomona, California.

On December 11, 2016, he played an acoustic benefit concert at Bimbos in San Francisco supporting New Light India’s “Boys Home Project”. Founded in 2000 by Urmi Basu, New Light India provides shelter, educational opportunities, recreational facilities, healthcare and legal aid for the girls and women in Kalighat, notorious for its red light district.

On 8 April 2019, Harper performed as a guest artist on the seventeenth season of American Idol during the second night of the “Top 20 Duets” episode. Harper sang with contestant Alejandro Aranda, playing “There Will Be a Light”.

On March 20, 2019, Mavis Staples announced a new album We Get By, featuring eleven tracks written and produced by Harper. The title track, which features Harper on vocals and in the music video, was released on May 15, 2019.