Claudia Acuña was born in Santiago in July 1971 and raised in Concepción, where the music around her was Chilean: the nueva canción repertoire of Víctor Jara and Violeta Parra, folk songs, pop, some opera. She was fifteen when she first heard Frank Sinatra, Erroll Garner and Sarah Vaughan, and the direction of her singing changed. She returned to Santiago in 1991 and established herself quickly on the city's small jazz scene, singing in its clubs and on radio broadcasts and sitting in with visiting musicians. Her first appearance on record came out of exactly that: the American guitarist Mark Elf cut an album in Chile for the Santiago label Alerce in 1994, a straight-ahead standards program running from "Giant Steps" to "Body and Soul" with the trumpeter Daniel Lencina, and Acuña sang on it.

She moved to New York in 1995 and spent the next several years working the jam sessions, often waiting until the small hours for a turn at the microphone. She became a regular at Smalls, Sweet Basil, the Zinc Bar and Metronome, and led her own band at the Jazz Gallery. The scene she landed in was being reshaped by a wave of Latin American players, and the musicians she met there account for most of her working life since. The most consequential was the pianist Jason Lindner, who became her musical director and has held the role for a quarter century. Another was the bassist Avishai Cohen, whose Stretch Records band she sang with, and with whom she cut the demo that brought her to Verve.

Cohen's three Stretch albums show the shape of that association precisely. On Adama (1998) her voice appears on one piece, the closing "Jasonity." On Devotion (1999) she is one of five singers credited on a record whose horn-and-rhythm sextet is otherwise the working band, and the album's credits assign no tracks to anyone, so how much of it she sings is not documented anywhere. On Colors (2000) she is credited explicitly as a guest, on two of the thirteen tracks, "Emotions" and "De Ye Tan Di," singing both alongside Cohen himself. None of the three is a band chair. The traffic ran the other way as well: Cohen played bass on her own Verve debut, in a trio with Lindner and the drummer Jeff Ballard.

Wind from the South (Verve, 2000) was that debut, and it set the pattern her leader records have followed since. Half of it is American songbook material, "Pure Imagination," "Prelude to a Kiss," "Bewitched," "My Man's Gone Now"; the other half is South American, including Violeta Parra's "Gracias a la Vida" and Ariel Ramírez's "Alfonsina y el Mar," with David Sánchez on saxophone, Diego Urcola on trumpet and Avi Lebovich on trombone as guests. Rhythm of Life followed on Verve in 2002 with a considerably heavier band: Dave Holland on bass, Jeff "Tain" Watts on drums, Sherman Irby on saxophone, a string quartet, and Billy Childs co-producing and playing piano alongside Lindner. Luna (MAXJAZZ, 2004) is the first record she produced herself, with Lindner, and the first weighted toward Spanish-language material throughout. In These Shoes (Zoho, 2008) is a co-billed album with the pianist Arturo O'Farrill, cut with an Afro-Cuban band including Yosvany Terry, Dafnis Prieto and Pedrito Martinez. En Este Momento (2009) was made for Branford Marsalis's label Marsalis Music and produced by Marsalis himself, and she took the Claudia Acuña Quartet, with Lindner, Juancho Herrera, Carlos Henderson and Yayo Serka, into Dizzy's Club at Jazz at Lincoln Center for five nights that April behind it.

She then stopped recording for a decade to raise her son, without leaving the bandstand: through those years she stayed the singer other leaders called. Turning Pages (2019), made in New York and issued in Chile, was the return, and it was nominated for the Latin Grammy for Best Jazz Album. Duo (Ropeadope, 2022) is the record the pause seems to have been building toward, nine Latin American songs sung one to one with a different partner on each: Kenny Barron, Christian McBride, Carolina Calvache, Fred Hersch, Regina Carter, Russell Malone and O'Farrill, plus an unaccompanied reading of Chick Corea's "Crystal Silence" and one original sung over her own bombo legüero. Ave de Luz: Chilean Jazz & Soul (Delfin, July 2026) narrows the frame further still, to Chilean material played on charango, trutruca and zampoña beside the piano trio, including a setting of a Gabriela Mistral poem.

Alongside the leader dates she has built a long list of guest appearances, and the pattern in them is consistent: a leader hands her one or two pieces on a record that is otherwise instrumental. She sings the title track of Joey Calderazzo's Amanecer (2007) and two others, and co-wrote two of the three; she sings the title track of Billy Childs's Rebirth (Mack Avenue, 2017) and co-wrote it. Elsewhere: backing vocals on two tracks of George Benson's Absolute Benson, "Radiant Moon" on Tom Harrell's Wise Children, "Curandero" on Guillermo Klein's Los Guachos II, one track each on Jason Lindner's Now Vs Now and Willie Jones III's The Next Phase. The exception is Avi Lebovich's Constant Chase (2002), where she sings seven of the nine tracks and is effectively a front-line voice in the band.

Recognition has come mostly from outside the American awards machinery. Chile gave her the keys to the city of Concepción, and the Chilean Chamber of Commerce in New York recognized her career in 2024. She has appeared on International Jazz Day programming with the Herbie Hancock Institute of Jazz, at the Newport Jazz Festival, and in Carnegie Hall's Musical Explorers education program, and she recorded an NPR Music Tiny Desk Concert in 2023. She has also worked outside jazz on occasion, most visibly on the house producer Louie Vega's Elements of Life records and a 2001 single with 3 Generations Walking, and she has served as a spokesperson for World Vision Chile.

Acuña's instrument is a warm, unhurried mezzo with very little vibrato and a habit of sitting slightly behind the beat, and the thing she is best known for is not range or speed but the decision about what a song is for. All About Jazz describes the tone as gleaming and burnished; what carries a record is the phrasing, which treats a Chilean nueva canción melody and a Rodgers ballad with exactly the same seriousness and refuses to make either exotic. She learned Sinatra, Erroll Garner and Sarah Vaughan at fifteen and Víctor Jara and Violeta Parra before that, and both traditions have stayed audible without ever fusing into a house style: Wind from the South alternates between them song by song, Duo strips the accompaniment to one instrument so the song itself has to carry, and Ave de Luz hands the record over to Chilean instruments entirely. She is also a working composer and lyricist, and the evidence is in other people's catalogs rather than her own, since it is her co-writes that opened Joey Calderazzo's Amanecer and titled Billy Childs's Rebirth. The role she has occupied most consistently for thirty years is the one a bandleader reaches for when an instrumental record needs a human voice on one piece and it has to be the right one.