Chiara Izzi was born May 22, 1985, in Campobasso, in Italy's Molise region. She studied classical piano for nearly a decade as a child, then shifted her focus to voice and jazz at seventeen, training at Campobasso's Thelonious Monk School of Jazz, where she first heard Ella Fitzgerald, Anita O'Day, Frank Sinatra and João Gilberto. She began performing professionally in Campobasso's jazz scene in 2004, and in 2008 released her first collaborative record, Lite Blue, with her band the BlueTime Quintet. She holds a bachelor's degree in Communications and Media from Campobasso and a Master's Degree in Jazz Music, earned with honors from the Conservatory of Frosinone in 2012.

A run of Italian jazz-competition placements built toward her international breakthrough: first prize at the Barga Jazz competition in 2009, the Lucca Jazz Donna award in 2010, and, in 2011, first prize at the Montreux International Jazz Festival Vocal Competition, judged that year by Quincy Jones. Jones told her afterward, "Sister you are very, very talented. You should go to the U.S., because you have to improve your craft." The win, the first by an Italian singer in the competition's history, came with a cash prize, a Shure microphone voucher, an invitation to perform at the 2012 Montreux Jazz Festival (where she opened for Paco de Lucia), and an all-expenses-paid recording session.

That session became her debut album, Motifs, released on Dot Time Records in September 2013 and recorded the previous year in Switzerland with pianist Andrea Rea, bassist Nicola Corso and drummer Gino del Prete. The eleven-track record moves between the American and Brazilian songbooks, Argentine tango and mainstream jazz vocalese and scat, sung across English, Italian, Spanish and Portuguese. All About Jazz critic C. Michael Bailey called her a "force of nature," and JazzTimes writer Jeff Tamarkin covered her Montreux win directly; the album was also reviewed in Downbeat-adjacent outlets including Jazz Weekly and the review site Acoustic Music.

Izzi relocated to New York City in 2014 and has built her career there since, performing rooms including the Iridium, Birdland, Smalls, the Blue Note, the 55 Bar and Rockwood Music Hall, and appearing at the Kennedy Center, the Aspen Jazz Festival and the Sarasota Jazz Festival. In February 2019 she released her second album, Across the Sea, co-billed with pianist Kevin Hays on Via Veneto Jazz and Jando Music: ten tracks mixing originals with songs by James Taylor, Pat Metheny and Henry Mancini. Discogs' full credit listing for the record documents an unusually deep sideman lineup for a vocal-jazz release: tenor and soprano saxophonist Chris Potter, guitarist Nir Felder, harmonica player Grégoire Maret, oud player Omer Avital, bassist Rob Jost, drummer Greg Joseph and percussionist Rogério Boccato. Hays, who also plays piano and Fender Rhodes on the record and trades vocals with Izzi on several tracks, has called her "one of the rare artists that we get the pleasure to meet a few times in our life." WRTI named it a Jazz Album of the Week on its release.

That same year, Izzi appeared as a guest vocalist alongside Cyrille Aimée and Janis Siegel on Brazilian guitarist Diego Figueiredo's Come Closer (2019, Stunt Records), a bossa nova and Latin jazz session led by Figueiredo.

In April 2020, Izzi won an Independent Music Award for Best Jazz Song with Vocals for her original composition "Circles of the Mind," drawn from the Across the Sea sessions. In December 2018 she had also recorded a live piano-and-voice duo set at Studio Nord in Bremen, Germany, with Neapolitan pianist Andrea Rea; two tracks from that session, "Poinciana" and "Miradas," were issued as advance singles in January and March 2022, ahead of the full seven-track album, Live in Bremen, released on Dot Time Records in March 2022 and reviewed in Downbeat. The record moves through Italian, Portuguese, Spanish and English repertoire, drawing on American, Argentine and Italian jazz sources alongside classical influences.

Izzi's singing sits inside the mainstream jazz tradition of standards interpretation and scat, but her catalog is defined as much by language as by repertoire: she has recorded in Italian, English, Spanish and Portuguese across her three studio-era albums, carrying the American and Brazilian songbooks, Argentine tango and her own Italian-language writing into a single, Mediterranean-inflected vocal identity that Dot Time Records has described as "high-level Euro-Pop" fused with "Mainstream Jazz Vocalese and Scat." Her two duo-centered projects, the horn-and-strings arrangements of Across the Sea (2019, with Kevin Hays) and the stripped-down piano-and-voice format of Live in Bremen (2022, with longtime pianist Andrea Rea), represent two ends of the same instinct: build each arrangement around a song's own language and story rather than a fixed band format. Her 2019 guest appearance on Diego Figueiredo's bossa nova session, alongside fellow vocalists Cyrille Aimée and Janis Siegel, sits inside the same Latin-jazz-facing side of her work.