Barrino began singing in her church at the age of 5. She was a member of The Barrino Family, a group that travelled and performed in the Carolinas and elsewhere in the American South. The group was popular but was taken advantage of in bad business dealings. Barrino has a young daughter, Zion Quari' Barrino, whom she had as a teenager on August 8, 2001. She dropped out of high school due to a rape incident that left her feeling embarrassed and harassed. However, she is currently enrolled in classes to receive her diploma.

Fantasia performing on American Idol Barrino made an immediate impression on American Idol with her stylized, gospel-influenced sound and her unconventional diction. Her audition version of John Fogerty/Tina Turner's "Proud Mary" made her an early favorite in the competition. Her standout performance during the course of the show was a prone, heartfelt staging of the Porgy and Bess standard "Summertime" that left her in tears from "feeling the song" and earned raves from the judges, as well as landing her on the Emmy Awards's 2004 list of greatest television moments. Nevertheless, Barrino's rise to the final two on American Idol was plagued with controversies including accusations of racism (when she and the two other well-praised African American female singers all landed in the bottom three, guest artist Elton John labelled the outcome racist), concerns over her being a poor role model, and charges of rigged voting and busy telephone signals. In the final performance of the season that formed the basis upon which America voted, Barrino offered a performance that drew effusive praise from the judges—including Simon Cowell's remarks that she was the best performer among the over 70 Idol champions crowned internationally since the show began its global competitions. Sixty-five million votes were cast in order to determine the winner on May 26, 2004, up from 24 million in 2003 . In the end Barrino beat out Diana DeGarmo by a margin of 1.3 million votes. Barrino participated in the U.S. tour with the other American Idol finalists and appeared in the 2004 Christmas special.