"I Believe" is the debut single released by singer and American Idolseason 3 winner, Fantasia Barrino, as well as the American Idolseason 3 runner-up, Diana DeGarmo. The song significantly helped Fantasia rise to fame. The song was co-written by former American Idolcontestant Tamyra Gray.

Fantasia sang "I Believe" on the finale of American Idol (season 3) as her last performance within the competition. Diana sang the song first, also on the finale, for her first performance of the night. Fantasia's final performance that evening is regarded by some fans and critics as one of the most outstanding performances in the show's history. Only her two performances of Summertime (which are considered by some to be among the best performances in the show's history) received more praise. Fantasia received outstanding praise and was declared the winner of American Idol by all three judges. The judges predictions came true and Fantasia was crowned American Idol the following evening. An ecstatic and tearful Fantasia performed her new single "I Believe" minutes after the announcement. Diana's performance was also well-received by the judges.

The song was an instant success for Fantasia when it was released on June 22, 2004. It performed well on the radio and sales charts of the United States and Canada debuting at number one in both nations. This made Fantasia the first artist in the history of the Hot 100 to debut at number one with a first record. "I Believe" is also the winner of three Awards. I Believeis noted for its inspirational lyrics.

The runner up of American Idol Season 3, Diana Degarmo, also sang this song during the final 2 showdown and in addition sang it during the finale as an encore performance. Although she did not win the competition, she did release the song on her single but did not release it on her debut album.

American Idol contestants, Lakisha Jones (season 6) and Syesha Mercado (season 7) sang this song during the inspirational song week.

When the song was released it debuted on the Hot 100 at number one. The CD was a substantial success in the U.S. and in Canada. In its debut week the single shattered the first week sales record for any single in 2004 in the U.S. "I Believe" was certified double platinum by the CRIA in Canada selling more than 80,000 units. It has sold 527,000 copies in the United States , making it one of the most successful single of 2004. "I Believe" was number one on the U.S single sales chart for eleven consecutive weeks and ten weeks in Canada, giving it the longest stay at number one on the chart by any Idolcontestant. "I Believe" also spent six consecutive weeks at number one on the U.S. R&B Single Sales chart. "I Believe" hit number one on more music charts than any other Idol contestant's debut single so far.