Jackson was born on June 23, 1956, in Baton Rouge, Louisiana the son of Julia, a homemaker, and Herman Jackson, a plant foreman. He graduated from Southern University in 1979 with a bachelor’s degree in music. His first marriage, to Elizabeth Jackson, was dissolved in 1990; they had one daughter named Taylor. In 1995, Jackson married Erika Riker, with whom he has two children, a daughter named Zoe and a son named Jordan. In 2014, Riker filed for divorce citing irreconcilable differences; it was finalized in 2019.

In 1985, Keith Richards was asked to provide music for the Whoopi Goldberg comedy vehicle Jumpin’ Jack Flash. Richards assembled an all-star band which included Aretha Franklin on piano and lead vocals and Jackson on bass guitar. This song was the fourth track on Aretha’s 1986 album titled Aretha. Jackson can be seen in the song’s video.

In the early 1980s, he played on three albums for Jean-Luc Ponty and with the rock band Taxxi. From 1986 to 1987, he was a session musician for the rock group Journey. Jackson played on Journey’s 1986 album Raised on Radio. He moved to Italy in the late 1980s and played on a record by Italian pop star Zucchero. The record, Zucchero and the Randy Jackson Band, was produced by Corrado Rustici who played guitar with Jackson on many albums in the early 1980s. He also played with Billy Cobham.

In the late 1980s, Jackson was still doing sessions. He was notably on the first solo album by famed session guitarist Steve Lukather. Jackson was a featured bass guitarist on five songs on Maze’s 1989 “Silky Soul” album. He also performed on several of Kenny G’s albums.

Jackson was the bass guitarist on the 1991 self-titled Divinyls album (which features the song “I Touch Myself”) as well as featured bassist on several tracks of Tracy Chapman’s 1992 release, Matters of the Heart. He performed on the singles “Bang Bang Bang”, “Open Arms”, and “Dreaming on a World”. That same year, Jackson also played bass on Bruce Springsteen’s song “Human Touch.”

Starting in 2002, Jackson was one of the panel judges on the Fox Network reality television series American Idol, along with Paula Abdul (2002–2009), Simon Cowell (2002–2010), Kara DioGuardi (2009–2010), Ellen DeGeneres (2010), Jennifer Lopez (2011–2012), Steven Tyler (2011–2012), Nicki Minaj (2013), Mariah Carey (2013), and Keith Urban (2013). As a result of Cowell’s departure, Jackson was left as the sole original judge on American Idol. His role was originally going to be reduced to that of a mentor, so the 2013 season would have all new judges, but it was later decided that he would remain as a judge for season 12. On May 9, 2013, Jackson announced that he would be leaving American Idol after twelve seasons due to him wanting to focus on other business ventures. On September 3, 2013, it was announced that Jackson would replace Jimmy Iovine as the in-house mentor on American Idol. He departed the series for good in November 2014.

In 2003, Jackson lost 114 pounds (52 kg) following gastric bypass surgery. He stated in a February 2008 television commercial that he has type 2 diabetes.

On March 11, 2008, Jackson released an album produced entirely by himself, titled Randy Jackson’s Music Club, Vol. 1. The album’s release was preceded by the single “Dance Like There’s No Tomorrow” sung by Paula Abdul. In 2009, Randy began working with former Idol finalist Kimberley Locke, producing her 4th album. The lead single, “Strobe Light”, was released March 16, 2010. In February 2010, Jackson participated in We Are the World 25 for Haiti as part of the chorus.

Jackson produced America’s Best Dance Crew, an American group dance competition and reality television show, which premiered on February 7, 2008 on MTV and was cancelled in 2010 due to declining ratings. Each week, the teams showcased their creative talents in choreography and their dance skills, and one crew was eliminated by the judges. The competition continued until the sole winning dance crew was awarded the title of America’s Best Dance Crew, and a cash prize of $100,000.