Marc Alan Johnson was born October 21, 1953, in Omaha, Nebraska, and grew up in Texas, where he took up bass at sixteen after already studying piano and cello. At the University of North Texas he played in the celebrated One O'Clock Lab Band and served as principal bassist of the school's symphony orchestra, and by nineteen he was working professionally with the Fort Worth Symphony. A stint touring with Woody Herman's band brought him to New York City, where a chance to sit in with pianist Bill Evans at the Village Vanguard changed the course of his career.

In 1978, at twenty-five, Johnson joined Bill Evans's trio, becoming the bassist in what turned out to be the pianist's final working group, alongside drummer Joe LaBarbera. He followed a line of bassists Evans had worked with going back to Scott LaFaro, Chuck Israels, Eddie Gomez, and Gary Peacock, and he has said the tune "Nardis" effectively became a nightly workshop for the trio, a place to keep discovering the bass's potential as a lead voice rather than pure accompaniment. Johnson remained with Evans until the pianist's death in September 1980, appearing on numerous recordings from that period, including the Grammy-winning studio album We Will Meet Again (1980, Warner Bros.), recorded in August 1979 and dedicated on its back cover to Evans's older brother, Harry L. Evans (1927–1979), a music educator whose suicide that year devastated the pianist; friends and biographers have long pointed to Harry's death as a factor in Evans's own rapid decline the following year. Johnson also appears on His Last Concert in Germany (West Wind), taped August 15, 1980, in Bad Hönningen — Evans's final recorded performance, made just weeks before his death. By his own account in later interviews, Johnson felt he was "in over his head" as a young sideman inheriting that chair, a feeling he has since revisited with more experience and, he's said, wishes he could unlearn.

After Evans's death, Johnson worked with Stan Getz (1981–1982) and guitarist John Abercrombie's trio (from 1983, later expanded with Peter Erskine and, on some dates, Michael Brecker), building a reputation as one of the most in-demand bassists in New York. In 1985 he formed his own group, Bass Desires, pairing two electric guitarists — John Scofield and Bill Frisell — over Peter Erskine's drums, an unusual, guitar-heavy front line AllMusic later compared to "one of the most auspicious [pairings] since John McLaughlin and Carlos Santana." The band's self-titled ECM debut, recorded in May 1985 at New York's Power Station and released in 1986, blended jazz with blues-rock and Americana textures well outside the era's mainstream fusion sound; a 1987 follow-up, Second Sight, recorded at Rainbow Studio in Oslo, extended the concept with a full album of originals from all four members. Bass Desires is now widely regarded as one of the defining ensemble records of 1980s ECM jazz, and the record that established Johnson as a bandleader and composer in his own right, distinct from his years in Evans's shadow.

Johnson's discography since has run in two parallel tracks: an extensive and unusually long-running sideman career, and a steady stream of leader dates, mostly for ECM. As a leader he released the harmonica-and-vibraphone duets album Two by Four (1989, EmArcy) with Toots Thielemans and Gary Burton; Right Brain Patrol (1992, JMT), a quartet record with guitarist Ben Monder and percussionist Arto Tuncboyaciyan dedicated to his daughter Francesca; and The Sound of Summer Running (1998, Verve), an all-star date pairing Bill Frisell and Pat Metheny on guitars with drummer Joey Baron — a lineup Johnson also toured with live in a rotating cast that, in some configurations, featured guitarist Steve Cardenas rather than Metheny or Frisell. On ECM he built a long-term partnership with Italian pianist Enrico Pieranunzi that produced numerous trio and duo recordings across three decades, alongside his own leader albums Shades of Jade (2005), Swept Away (2012), and Overpass (2021) — his first leader date in roughly a decade, an unaccompanied-bass showcase recorded in São Paulo.

Shades of Jade proved to be a career high point commercially and critically: it was named one of Time magazine's "5 CDs That Really Swing" in its October 17, 2005, issue and won the Danish Music Award for Best Foreign Release that year. Both Shades of Jade and Swept Away feature Johnson's wife, Brazilian pianist and singer Eliane Elias, alongside saxophonist Joe Lovano and drummer Joey Baron; the two frequently tour and record together, and Johnson has produced several of Elias's own albums, winning Grammy Awards as co-producer of her Made in Brazil (2016) and Dance of Time (2017). One of their joint projects, Elias's Something for You: Sings & Plays Bill Evans (2008, Blue Note), carries a direct link back to Johnson's own history with the pianist: it includes two previously unrecorded Bill Evans compositions, "Evanesque" and "Here Is Something for You," which Johnson had kept on a cassette Evans gave him not long before he died, and which surfaced only decades later.

Across more than four decades Johnson's sideman credits extend well beyond Evans, Getz, and Abercrombie to include Lyle Mays, Fred Hersch, Paul Motian, Lee Konitz, Joe Lovano, Mel Lewis, John Taylor, and a 1999 live incarnation of the fusion group Steps Ahead alongside Mike Mainieri, Bob Berg, Eliane Elias, and Peter Erskine. He remains one of the most widely traveled and recorded bassists of the post-Evans generation, still active as both leader and first-call sideman.

Johnson has named Scott LaFaro — the young bassist whose radical melodic conception reshaped the Bill Evans Trio a generation before Johnson's own tenure — as his single most formative influence, citing LaFaro's "unique and natural" sound, his "melodic and inventive" phrasing, and the "horn-like quality" of his soloing as a model Johnson worked to internalize. That lineage shows in Johnson's own emphasis on clean intonation, precise time feel, and self-editing over sheer note count, an approach built for both accompaniment and lead voice work. His years in Evans's final trio gave him a direct, formative connection to one of jazz piano's most influential harmonic thinkers, while Bass Desires revealed a second, rockier side of his musical personality: a willingness to blend blues-based electric guitar textures and backbeat energy into an otherwise straight-ahead jazz vocabulary, years before that kind of hybrid became commonplace. Between those two poles — the harmonic sophistication of the Evans lineage and the guitar-forward, genre-blurring instincts behind Bass Desires — sits the rest of his catalog: long-running, more chamber-like duo and trio work with Enrico Pieranunzi on one end, and Brazilian-inflected, groove-driven leader dates with Eliane Elias on the other.