Nilson Carlos Ruiz Matta grew up in São Paulo in the late 1950s in a musical household: his mother was a classical pianist and his older brother played drums. By his own account, at age ten he heard his mother's records of bossa nova, Ray Conniff, Frank Sinatra, and Louis Armstrong and announced "I like the fat sounds," and when he later spotted an upright bass in a music shop he called it "a big violin." He moved to Rio de Janeiro in 1970 and studied bass formally at the Federal University of Rio de Janeiro (UFRJ) under Sandrino Santoro, one of Brazil's leading classical bassists. Through the 1970s and into the early 1980s he worked as a first-call bassist in Rio's popular-music and MPB scenes, playing behind João Gilberto, Hermeto Pascoal, Roberto Carlos, Chico Buarque, Nana Caymmi, João Bosco, Johnny Alf, Helio Delmiro, Luiz Bonfá, and the vocal group MPB4. In the late 1970s he and drummer Duduka Da Fonseca also played together in an amateur soccer league in Rio; a broken left arm from the pitch in 1982 sidelined Matta's playing for a full year before he recovered.

Matta relocated to New York City in 1985 and quickly became one of the most in-demand Brazilian musicians on the American jazz scene. He co-founded The African-Brazilian Connection with pianist Don Pullen, a group whose three Blue Note albums, Kele Mou Bana (1992), Ode to Life (A Tribute to George Adams) (1993), and Live... Again (Live at Montreux) (1995), gave him his first sustained visibility as a jazz sideman in the United States. Through the same years he recorded with Claudio Roditi on Gemini Man (1988) and Two of Swords (1991), and with Paquito D'Rivera on Return to Ipanema and Tico! Tico! (both 1989), alongside further work with Slide Hampton, Herbie Mann, Mark Murphy, Oscar Castro-Neves, Don Friedman, Paul Winter, and Gato Barbieri.

The most consequential move of Matta's New York years came in 1986, when he joined guitarist Romero Lubambo and drummer Duduka Da Fonseca to found Trio da Paz. Working continuously for close to four decades, the group became one of the most respected working units in Brazilian jazz, recording nine studio albums: Brasil From The Inside (1992, Concord Picante), Black Orpheus (1994, Kokopelli Records, with guest flutist Herbie Mann and trumpeter Claudio Roditi), Partido Out (1998, Malandro Records), Cafe (2002, Malandro Records), Somewhere (2006, Blue Toucan Music), Harry Allen Meets Trio Da Paz (2007, Swingbros), Night of My Beloved (2007, credited to George Garzone & Trio Da Paz, Venus Records, with pianist Kenny Werner), Live at JazzBaltica (2008, MAXJAZZ, with vibraphonist Joe Locke), and 30 (2016, ZOHO), marking the group's thirtieth anniversary. Partido Out won the Jazz Journalists Association Award for Best Brazilian Jazz Album in 2002, and 30 was nominated for the Grammy Award for Best Latin Jazz Album at the 59th Annual Grammy Awards. Da Fonseca's own JazzProfiles.com profile covers the trio's broader history and Da Fonseca's individual career in more detail.

From 1995 through 1998 Matta worked extensively with saxophonist Joe Henderson, appearing on Henderson's 1996 album Big Band, which won the Grammy Award for Best Large Jazz Ensemble Performance in 1998. Cellist Yo-Yo Ma then selected Matta for Obrigado Brazil (2003, Sony Classical), a bossa nova and Brazilian-song collaboration that won the Grammy Award for Best Classical Crossover Album in 2004; Matta also appeared on the companion release Obrigado Brazil: Live in Concert and on the resulting two-year world tour, and later rejoined Ma for Songs of Joy & Peace (2008).

Alongside Trio da Paz, Matta built a substantial catalog under his own name. He co-led Encontros - Meetings (2000, Malandro Records) with harmonica and vibraphone player Hendrik Meurkens, backed by Romero Lubambo, Duduka Da Fonseca, and percussionist Café. WalkIng With My Bass (2006, Blue Toucan Music) gathered an unusually large cast of Brazilian and American musicians, including Kenny Barron, Ivan Lins, Rosa Passos, João Bosco, Joyce, Jeff "Tain" Watts, and Claudio Roditi. He followed with Green Heart (2007, credited to Nilson Matta, Zé Luis, and Paulinho Braga) and, billed as Nilson Matta's Brazilian Voyage, Copacabana (2010, ZOHO) with tenor saxophonist Harry Allen and flutist Anne Drummond. Mojave (2011, Motéma, subtitled Jazz Therapy Vol. 3) was co-billed to Matta and guitarist Roni Ben-Hur, with drummer Victor Lewis and percussionist Café completing the quartet; Matta plays bass across the entire album. In 2013 he released Black Orpheus on Motéma, a reimagining of the classic film score featuring Randy Brecker on trumpet, Anat Cohen on clarinet, and Kenny Barron on piano, and in 2015 he released East Side Rio Drive (Krian Music Group/World Blue Records) with Romero Lubambo. Separately, with Da Fonseca and pianist Helio Alves, Matta formed The Brazilian Trio, releasing Forests (2008, ZOHO, nominated for a Latin Grammy in 2009) and Aguas Brasileiras (2020, ZOHO).

Matta has taught extensively alongside his performing career. He is a member of the International Society of Bassists and a regular guest at its conventions, has taught at the Litchfield Jazz Camp, and serves as Artistic and Music Director of the Samba Meets Jazz Workshops, with vocal and instrumental programs in Bar Harbor, Maine, on Boston's North Shore, and at international locations. He lives in Cresskill, New Jersey.

Matta's bass playing carries the specific weight of Rio's samba and partido alto traditions into a jazz rhythm section rather than treating them as decoration on top of one, an approach he built first as a first-call session player in Brazil's popular-music scene and then as a session and touring bassist in American jazz. That grounding is the foundation of Trio da Paz's nearly forty-year partnership with Romero Lubambo and Duduka Da Fonseca, and it is audible across his outside work too: Joe Henderson, Yo-Yo Ma, and Don Pullen each drew on his ability to make Brazilian rhythm feel like a native part of a jazz or classical-crossover setting rather than a guest idiom layered onto it. His teaching, through the International Society of Bassists and his own Samba Meets Jazz Workshops, extends that same instinct into formal instruction in how Brazilian rhythm and jazz vocabulary combine.