Simona Bencini was born in Florence on August 31, 1969. At seventeen she joined a group of friends staging The Rocky Horror Picture Show as a chorus singer, and in 1989 she sang with the Hi-NRG dance group Monnalisa, which cut two tracks for the Japanese market. In 1990 she met Dirotta su Cuba, a Florentine acid jazz and funk band founded the year before by the keyboardist Rossano Gentili and the bassist Stefano De Donato. She started as a backing vocalist and became the band's lead singer in 1992.

Dirotta su Cuba made her name. The single "Gelosia" (1994) was followed by the album Dirotta su Cuba (CGD East West, 1995), which Italian Wikipedia reports as certified platinum and Discogs tags Jazz-Funk, Contemporary R&B and Soul. Nonostante tutto... followed in 1996. In 1997 the band entered the Sanremo Festival with "È andata così," accompanied on stage by the harmonica player Toots Thielemans, and an album of the same name appeared that year. Dentro ad ogni attimo (2000) was the third studio set. De Donato left in 2000, and Bencini recorded Fly (2002) before leaving to work as a soloist.

The solo work that followed was pop and soul, and it was a success on those terms. Sorgente (Atlantic, April 8, 2005) is described by Italian Wikipedia as a soul and R&B record with gospel-style vocal counterpoint; its first single, "Questa voce," was written by Pacifico and carries piano by Stefano Bollani, and the album includes a duet with Irene Grandi. In 2006 she returned to Sanremo with "Tempesta," co-written with Elisa and performed in an English-Italian version with Sarah Jane Morris. She was a regular guest on Italian television, duetted with Ron, Massimo Ranieri and Franco Califano, and played Mary Magdalene in Massimo Romeo Piparo's staging of Jesus Christ Superstar from October 2010 to February 2011. Since 2019 she has been one of the hundred judges on the Canale 5 talent show All Together Now, and in 2021 she took the part of Marta Sandoval in the Italian version of the animated film Vivo.

Her jazz work runs alongside all of that and is documented in recordings. In 2001 she sang "In cerca di te (Perduto amor)," track 14 on Stefano Bollani's Abbassa la tua radio (Ermitage), a collection of 1930s Italian songs, and Italian Wikipedia says the album took her to the Premio Tenco and Umbria Jazz Winter that year. In 2007 she was a guest, with Irene Grandi, on the Parco della Musica Jazz Orchestra's Jazzitaliano Live 2007 (Casa del Jazz), directed by Maurizio Giammarco; Italian Wikipedia says she sings two songs made famous by Mina, "Non gioco più" and "Sabato notte."

In 2009 she formed a jazz quartet with the pianist and singer Mario Rosini, billed as the L.M.G. Quartet (Last Minute Gig): Rosini, the drummer Mimmo Campanale, the double bassist Giuseppe Bassi and the alto saxophonist Gaetano Partipilo. Their album Spreading Love came out on Groove Master Edition, the label of Gegè Telesforo (Discogs dates the CD October 22, 2010; Italian Wikipedia and All About Jazz give 2011). Its ten tracks mix Gershwin's "The Man I Love," "You Don't Know What Love Is," "I'm Beginning to See the Light," a title song and a "Geraldine" with new lyrics she wrote for her daughter, plus a duet with Rosini on "Stay." Reviewing it in April 2011, All About Jazz Italy described a set that joins mainstream jazz with fresh world rhythms, with the quartet staying discreet behind the voice. Her own biography calls it her first jazz album.

She also rejoined Dirotta su Cuba in 2009 for the twentieth-anniversary Back to the Roots tour, which closed at the Blue Note in Milan, and the original line-up reunited formally in 2012. The band opened the Estival Jazz festival in Lugano in 2014 and played Umbria Jazz Winter in 2015 and 2016. Studio Sessions Vol. 1 (September 23, 2016) re-recorded the debut album and added new songs, with guests including Fabrizio Bosso, Gegè Telesforo, Mario Biondi, the vocal group Neri per Caso, the bassist Federico Malaman and the guitarist Riccardo Onori. In 2018 she was among the billed artists on Historias (Nadir Music), a bossa nova and contemporary jazz release that also lists the guitarist Alessio Menconi and the pianist Dado Moroni. In June 2025 the band, in a renewed line-up, played Rome's Casa del Jazz.

Her second jazz album, Unfinished, was released on October 8, 2021 on her own label, Sherazade Sound. The songs are originals and the playing is by jazz musicians: Discogs credits the pianist Julian Oliver Mazzariello on four songs, Mario Rosini on piano for two, including Ellington's "It Don't Mean a Thing," and Antonio Faraò on piano for "Non so se tu," a song with words by Giorgio Calabrese and music by Bruno De Filippi, who also plays harmonica on it. The trumpeter Fabrizio Bosso plays on the single "Moonlight on My Mind," and Gaetano Partipilo co-wrote "Angel's Lullaby" with her. Italian Wikipedia also names Max De Aloe, Dario Rosciglione and the drummer Luca Alemanno among the players. A limited vinyl edition of 300 numbered copies came out on Cimbarecord.

Bencini is a singer who came to jazz from Italian funk and pop, and her career is organized that way: the band records and the television work are pop and soul, and the jazz records are separate projects with their own musicians. On the Dirotta su Cuba records the setting is Italian acid jazz, a keyboard and horn funk with soul vocals that Discogs tags Jazz-Funk. On Spreading Love and Unfinished she works in a conventional small-group jazz frame: standards by Gershwin and Ellington, ballads, a South American-flavored number such as "Capoeira," and original songs, with piano-led accompaniment.

Her jazz connections are Italian, mostly Florentine and Roman: the collaboration with Stefano Bollani in 2001, the Casa del Jazz appearance with the Parco della Musica Jazz Orchestra, Gegè Telesforo's label, and the players on Unfinished. She is not an improvising-first jazz singer, and her catalogue is far larger on the pop side than on the jazz side, with two albums from her jazz projects against a long run of band, pop and television work. The jazz-funk thread through the Dirotta su Cuba years and those two albums are what place her in the jazz-adjacent field.