Her father was a classical pianist who was under the guidance of Vladimir Horowitz. Her biological background is vast as it includes German, Italian, Irish and Cherokee.
At the age of fifteen, she won the 1983 Star Search talent show.
In 1987, she was signed to Chrysalis Records. She first performed the song "Jackie" on the Summer School soundtrack and caught the eye of John "Jellybean" Benitez who asked her to be the lead vocalist on two songs on his 1987 album Just Visiting this Planet. One of the song, "Who Found Who", was a hit woldwide reaching the Top 20 in many countries in addition to great club success. At the same time, Fiorillo released her self-titled debut album that she promoted with the help of the pop single "How Can I Forget You" but she did not manage to get the same success.
She released her second album I Am in 1990 recorded at Prince's Paisley Park recording studio after she had contributed, as a backing vocalist, to the soundtracks of Grafitti Bridge and Batman. Several songs from the album were produced and written by Prince himself. The album scored a top 30 hit in the U.S. with "On the Way Up". Fiorillo also appeared on Prince's album Diamonds and Pearls being the backing vocalist on two songs.
She then mainly did back-up singing. Fiorillo sang back-up for Savage Garden on the Superstars and Cannonballs tour and for Billie Myers among others.
Metal Gear series
As a lead singer, Fiorillo sang "Don't be Afraid" for Metal Gear Solid 3: Snake Eater.