Leona Lewis was born in Highbury, in the London borough of Islington, to parents Aural Josiah, an Afro-Caribbean Guyanese youth worker, and Maria Lewis, a Welsh social worker. At the age of five, she attended the Sylvia Young Theatre School,and later the Italia Conti Academy and the BRIT School. Lewis wrote her first song at the age of twelve, and won a number of talent competitions. After leaving school, Lewis took a number of jobs to pay to get into a recording studio, including waitressing and several receptionist jobs. She wrote and recorded a number of songs including a demo album of her own songs called Twilight, but the album was never released. When she was fifteen years old, she recorded a version of Minnie Riperton's "Lovin' You" with music producer Marley J. Wills, after which Lewis and Wills were invited to the U.S. by Sony. Wills commented that "Leona could hit the notes and I think she did it better than the original." When her career seemed to be going nowhere, she was considering quitting the music industry until her boyfriend persuaded her to enter The X Factor.

Her debut album, Spirit, was released in Europe in November 2007, and became the fastest-selling debut album ever in both the United Kingdom and Ireland.Released in North America in April 2008, Spirit debuted at number one in the US Billboard 200 chart and made Lewis the first British artist to top the chart with a debut album. With her album reaching number one in at least three continents and nine countries, Lewis has had the most successful launch of any television talent show contestant ever.

Lewis' third single, a double A-side featuring "Better in Time" and "Footprints in the Sand", was released in the United Kingdom in March 2008, in aid of Sport Relief, and she visited South Africa for the charity. The songs reached a peak of number 2 in the UK singles chart selling over 40,000 copies in its first week of physical release. As a part of Sport Relief, Lewis has set up a website, yougivemestrength.com, for people to share their inspirational stories. It has been reported that Lewis is planning a £15 million world tour in 2010. A second album is planned for release in 2009. On 27 March 2008, "Bleeding Love" became number one in the United World Chart. On 23 April 2008, Lewis performed "Bleeding Love" on the seventh series of American Idol during one of the results nights of the show. She was also a presenter at the MTV Australia Awards 2008 on 26 April 2008, and a special guest performing "Bleeding Love" again at the finale of So You Think You Can Dance Australia on 27 April 2008.