Brian Jackson was born in Brooklyn on October 11, 1952, to Clarence Jackson, a New York State parole officer, and Elsie Jackson, a librarian at the Ford Foundation. He grew up in Bedford-Stuyvesant, Flatbush and Crown Heights. He wanted to play drums, his mother would not have them in the apartment, and piano was the compromise. He studied for seven years in Fort Greene with his mother's childhood teacher, Hepzibah Ross, who kept him on as a scholarship student when the family could no longer pay. He attended Erasmus Hall High School from 1965 to 1969, played his first paid job in a Harlem church at about fourteen, and later took up the flute after a nerve injury in his shoulder ended his saxophone playing.

At Lincoln University in Pennsylvania he met the poet and singer Gil Scott-Heron, and the two formed a band called Black & Blues, the nucleus of the group that would later record as the Midnight Band. Jackson played on Scott-Heron's first two studio albums for Flying Dutchman. Pieces of a Man was recorded in April 1971 at RCA Studios in New York with producer Bob Thiele, a rhythm section that included Ron Carter on bass and Bernard Purdie on drums, and Hubert Laws on flute. Free Will followed in 1972, with Jackson credited on acoustic and electric piano, flute, bells and vocals.

Jackson and Scott-Heron left Flying Dutchman in early 1973. Scott-Heron said the break came because Thiele would not give Jackson co-billing, and Winter in America, released in May 1974 by the independent Strata-East label, was the first record to carry both names. It was recorded in September and October 1973 at D&B Sound in Silver Spring, Maryland, and entered the Billboard jazz albums chart at number six. Its single "The Bottle," built on a Caribbean-tinged groove with Jackson's flute and Scott-Heron on electric piano, became an underground hit and led to a contract with Arista.

At Arista the pair worked with the Midnight Band as an eight-piece group. The First Minute of a New Day (January 1975), From South Africa to South Carolina (November 1975, with the single "Johannesburg"), It's Your World (November 1976, part live and part studio), Bridges (1977) and Secrets (1978) all charted on the Billboard jazz albums list, and Secrets reached number three there. The last album of the partnership was 1980, recorded from August to October 1979 and released in February 1980. Scott-Heron and Jackson produced it with Malcolm Cecil. Jackson arranged the songs and played Cecil's TONTO synthesizer, with Harvey Mason among the studio musicians. The two went their separate ways that year after a decade of writing, recording and touring together.

Jackson spent the 1980s working in the studio and on the road rather than as a front man. By his own account he was turned down by fifteen labels with his own music. He is credited on keyboards on Kool & the Gang's Something Special (1981) and as a musician on Roy Ayers's Drive (1988), played keyboards on and co-produced Will Downing's self-titled debut (1988), produced further tracks for Downing in 1989, and produced three tracks on Gwen Guthrie's Hot Times (1990). He also toured with Phyllis Hyman and Bobbi Humphrey. English Wikipedia lists him as a programmer and project manager in the information technology division of the City of New York from 1983 to 2017.

His solo career resumed in 2000 with Gotta Play, which had guest appearances from Roy Ayers and Scott-Heron. In 2013 he led the New Midnight Band on Evolutionary Minded, a record with M1 on Motéma, subtitled as furthering the legacy of Scott-Heron, and in August 2021 he joined Ali Shaheed Muhammad and Adrian Younge for Jazz Is Dead 008. This Is Brian Jackson (BBE, May 27, 2022), his first full solo album in more than twenty years, was produced by Daniel Collás of the Phenomenal Handclap Band, whom Jackson met in 2018 during a residency at the Nublu club in the East Village. It included three songs Jackson had written in the 1970s.

BBE then issued a run of singles in 2025 and early 2026 before Now More Than Ever, released May 29, 2026. Louie Vega and Kenny "Dope" Gonzalez of Masters At Work produced it, and it was recorded in February and March 2024 at Manhattan Center Studios in New York. The nineteen tracks revisit songs from the Scott-Heron years with new vocalists and spoken-word guests, among them Raheem DeVaughn, Lisa Fischer, Rahsaan Patterson, Omar, Moodymann and Black Thought, who contributes new lyrics and vocals to "The Revolution Will Not Be Televised." Flute on that track comes from Jackson and Ivan Renta. Jackson shares the lead vocal with Omar on "The Bottle" and sings lead on a second version of "Home Is Where the Hatred Is."

Most of Jackson's career sits in soul, funk and spoken-word records rather than in the jazz mainstream, and the Scott-Heron albums are the clearest case: poems and protest songs set over Fender Rhodes, flute and a working rhythm section. What ties them to jazz is the way Jackson built the music. His piano-based arrangements were rooted in jazz and the blues, his flute carried the hooks on "The Bottle" and "Your Daddy Loves You," and the Midnight Band played as a small jazz-funk ensemble. The albums charted on the Billboard jazz list, and critics later traced their sound forward to acid jazz and, through sampling, to hip-hop. He composed most of the music the duo recorded, and the dispute over co-billing at Flying Dutchman is the reason the records from Winter in America onward carry both names. In 2022 he named Masters At Work, Louie Vega and Kenny Gonzalez as inspirations, and the club-leaning arrangements on his recent records reflect it.