Paul Milton Jackson Jr. was born in Los Angeles on December 30, 1959, and grew up near the University of Southern California campus. He began as a child actor, with a guest role on the sitcom Good Times, and played in local bands from his early teens, including a family group with his siblings. He studied music at USC. His own account of his influences names Earl Klugh, George Benson, Lee Ritenour, George Duke and Ray Parker Jr., and he credits Patrice Rushen as his mentor. He is not the bassist Paul Jackson of Herbie Hancock's Headhunters, and he is not related to Michael Jackson, on three of whose albums he played.

Jackson has been a working recording musician since 1976, and most of his career has been spent in the pop and R&B studios of Los Angeles. His jazz-side credits start early. He is one of two guitarists on Donald Byrd's Thank You...For F.U.M.L. (Funking Up My Life) (Elektra, 1978) and is credited on Patrice Rushen's Patrice (1978) and Pizzazz (1979). He plays guitar on three tracks of Stan Getz's Children of the World (Columbia, 1979) and rhythm guitar on Ella Fitzgerald's Ella Abraça Jobim (Pablo, 1981), her Antonio Carlos Jobim songbook.

The pop and R&B work is the larger body of it, and it is stated here plainly. On Michael Jackson's Thriller (1982) he is credited on guitar on three tracks, "Beat It," "P.Y.T. (Pretty Young Thing)" and "The Lady in My Life"; on Bad (1987) on "Another Part of Me," "Dirty Diana" and "Leave Me Alone"; and on Dangerous (1991) on "Why You Wanna Trip on Me." Thriller won the Grammy for Album of the Year. He plays on Whitney Houston's Whitney Houston (1985), Whitney (1987) and I'm Your Baby Tonight (1990), on Madonna's True Blue (1986), Barbra Streisand's Emotion (1984), Lionel Richie's first solo album (1982), Anita Baker's The Songstress (1983) and Rapture (1986), and on albums by the Temptations, Patti LaBelle, Aretha Franklin, Natalie Cole, Donna Summer, Kenny Rogers and Chicago. His credits run to well over a hundred artists.

The same studio circuit fed the contemporary-jazz records of the 1980s. He plays on Earl Klugh's Low Ride (1983), Soda Fountain Shuffle (1985) and Whispers and Promises (1989); on Al Jarreau's High Crime (1984); on Ramsey Lewis and Nancy Wilson's The Two of Us (1984); on George Duke's Thief in the Night (1985), where he is credited on guitars on eight of the nine tracks; on George Benson's 20/20 (1985), While the City Sleeps... (1986) and Twice the Love (1988); and on the Bob James and David Sanborn collaboration Double Vision (1986), alongside Eric Gale and Marcus Miller.

His own recording career began with Atlantic, which, by AllMusic's account, gave him a solo deal in 1986. I Came to Play (1988) earned a Grammy nomination for Best R&B Instrumental Performance (Orchestra, Group or Soloist) at the 31st Grammy Awards in 1989, which Chick Corea's "Light Years" won. Out of the Shadows (1990) and A River in the Desert (Atlantic Jazz, 1993) followed. On the latter he produced tracks 2 through 11 and arranged most of them, with Stanley Clarke on acoustic bass, Harvey Mason and Leon "Ndugu" Chancler on drums, George Duke and Bobby Lyle on piano, Jeff Lorber and Greg Phillinganes on keyboards and Gerald Albright on flute. He moved to Blue Note with Never Alone: Duets (recorded for Japan's Pony Canyon and Sweet Basil, released by Blue Note on May 14, 1996 in the United States), The Power of the String (2001) and Still Small Voice (May 20, 2003), which reached No. 29 on Billboard's Jazz Albums chart and features Patrice Rushen on electric piano, Harvey Mason on drums and Sheila E. on percussion. Lay It Back (Branch, October 6, 2008) and Stories from Stompin' Willie (June 16, 2016, produced by Jackson himself) came out on independent labels. His official biography credits two singles from Stompin' Willie, "Down the Road" and "B.F.A.M. (Brothers From Another Mother)," with reaching No. 1 on the charts it cites. A single, "City of Refuge" with Jeff Lorber (August 6, 2021), was followed by the EP Stompin' Willie presents More Stories, part 1 (April 15, 2022).

Television has been a second steady job. He played guitar in Rickey Minor's Tonight Show Band during Jay Leno's second run on The Tonight Show (2010 to 2014) and in the band on American Idol. In 2013 he played on nine tracks of Daft Punk's Random Access Memories, including "Get Lucky," and shares the writing credit with Nile Rodgers on the opening track, "Give Life Back to Music." The album won Album of the Year and "Get Lucky" won Record of the Year at the 56th Grammy Awards in January 2014. Back in jazz, he plays guitar on one track of Marcus Miller's Renaissance (Concord Jazz, 2012) and on three tracks of the Stanley Clarke Band's Up (Mack Avenue, 2014).

Since 2019 he has been the guitarist of Jazz Funk Soul. Saxophonist Everette Harp, keyboardist Jeff Lorber and guitarist Chuck Loeb formed the group in 2014; Loeb passed away in 2017, and Jackson took the guitar chair for Life and Times (Shanachie, January 25, 2019), then Forecast (August 5, 2022), which closes with a tribute to Loeb titled "CLS (For Charles Samuel Loeb)," and Simpatico (July 11, 2025). He has also taught at his alma mater: he was the first holder of the Garn Family Contemporary Music Artist-in-Residence fund at the USC Thornton School of Music, serving as artist in residence in the 2016-17 school year, and his official biography also lists him as an Assistant Professor of Practice in Thornton's Popular Music Division. As of November 1, 2026, his official site lists current tour dates as a solo artist, with Jazz Funk Soul, and as a special guest, and offers an instructional video series in which he demonstrates guitar parts from records he played on.

Jackson is first of all a studio rhythm guitarist. He appears in Joachim Vogel's 1995 book Masters of Rhythm Guitar, which Wikipedia cites for his work with Michael Jackson and Whitney Houston, and in the studios his job was funk and R&B parts that served the song, for singers and producers who kept calling him back. His solo records carry that sound toward smooth jazz and add covers such as Marvin Gaye's "Inner City Blues" on The Power of the String and the Commodores' "Easy Like Sunday Morning" on Lay It Back. AllMusic files him as a longtime session jazz guitarist whose solo work found favor in the smooth jazz world by the 1980s. His jazz-side credentials are the Blue Note albums, the sideman dates listed above with Stan Getz, Ella Fitzgerald, Donald Byrd, Stanley Clarke, George Duke, George Benson and Marcus Miller, and his chair in Jazz Funk Soul. Herbie Hancock, quoted on his own site, calls him "The guitarist who can play anything." The influence his biography names first is Wes Montgomery, whom he never met, together with the Los Angeles generation just ahead of him: Gary Bell, Al McKay and Ray Parker Jr., with Lee Ritenour and his mentor Patrice Rushen.