Leona Louise Lewis OBE (born 3 April 1985) is a British singer, songwriter, and actress. Born and raised in London, she later attended the BRIT School for Performing Arts and Technology in Croydon. Lewis achieved national recognition when she won the third series of the ITV talent show The X Factor in 2006, winning a £1 million recording contract with Syco Music. Her winner's single, a cover of Kelly Clarkson's "A Moment Like This", peaked at the top of the UK Singles Chart for four weeks and broke a world record by reaching 50,000 digital downloads within 30 minutes. In February 2007, Lewis signed a five-album contract in the United States with Clive Davis's record label, J Records.

Lewis's success continued with the release of her debut studio album, Spirit (2007), which was certified 10× platinum in the UK and became the fourth best-selling album of the 2000s and one of the best-selling albums in UK chart history. The lead single, "Bleeding Love", spent seven weeks at the top of the UK Singles Chart and was Britain's best-selling single of 2007. Her second studio album, Echo (2009), entered at the top of the UK Albums Chart. In 2011, Lewis released the single "Collide", a collaboration with Swedish DJ Avicii, and her debut extended play, Hurt: The EP. Her third studio album, Glassheart (2012), marked a new creative direction for Lewis, drawing inspiration from dubstep and electronic music. She began to record material for her first Christmas album during her Glassheart Tour, which took place in mid 2013. Christmas, with Love was released later that year and its lead single, "One More Sleep", peaked at number three on the UK Singles Chart.

In 2014, Lewis made her film debut in Walking on Sunshine, and her fourth studio album, I Am, was released the following year. In 2016, she made her Broadway debut as Grizabella in the revival of Andrew Lloyd Webber's musical Cats, and the following year, she signed a modelling contract with Wilhelmina Models. She then collaborated with Calum Scott on the single "You Are the Reason" (2018), and had a recurring role on the American television series The Oath (2019). In 2021, Lewis joined the Paramount+ show Queen of the Universe as a judge.

According to her record company, as of 2021, Lewis has sold over 35 million records worldwide. She is the first British female solo artist to reach the top five with eight singles, surpassing Olivia Newton-John's record of seven. Lewis has won two MOBO Awards, an MTV Europe Music Award, and two World Music Awards. She is also a six-time BRIT Award and three-time Grammy Award nominee. Aside from her music and acting career, Lewis has publicly supported various charitable causes, particularly animal rights; she is also vegan.

Leona Louise Lewis was born on 3 April 1985 in London, to a father of Afro-Guyanese descent and a mother with Welsh, Irish and Italian ancestry. She has an older half-brother, Bradley, and a younger brother, Kyle. Noticing Lewis's passion for singing, her parents enrolled her at the Sylvia Young Theatre School and later at the Italia Conti Academy of Theatre Arts, the Ravenscourt Theatre School and the BRIT School for Performing Arts and Technology until they could no longer afford to do so, making cutbacks when necessary to help their daughter achieve her aspiration of being a singer.

At the age of 17, Lewis decided to leave BRIT School to "get out there" and pursue a career in music. By then, she had already begun to write and record her own material, and she worked as a receptionist at a solicitor's office and as a Pizza Hut waitress in order to fund the studio sessions. At 18, Lewis secured a lead role in The Lion King theatre show in Paris; however, she withdrew after injuring her back while she was ice-skating.

Lewis recorded a demo album, called Twilight, in collaboration with Spiral Music, a production company based in Fulham, but it failed to secure her an album deal with any record companies. Although the album was never released commercially, Lewis performed a couple of the tracks live on BBC Radio 1 music station in 2004. Another demo album was recorded under license from UEG Entertainment, Best Kept Secret, which have reportedly claimed to have spent £70,000 trying to launch Lewis's career with no success. A track from the album, "Private Party", became a hit on the underground urban music scene in London in 2005. Speaking about her struggle to secure a record contract, Lewis said, "I tried to secure a record deal by doing things my own way. I worked very hard but I never managed to land a contract. That's why I decided to audition for The X Factor. It's programmes like these which provide the best place to showcase fresh new talent."

Lewis auditioned for the third series of The X Factor in 2006, singing "Over the Rainbow" for judges Simon Cowell, Louis Walsh, Sharon Osbourne and guest judge Paula Abdul. She was placed in the 16–24 category, with Cowell as her mentor. Throughout the course of the show, Lewis was compared with artists such as Mariah Carey, Whitney Houston and Celine Dion, performing songs by all three of them. Lewis defeated Ray Quinn to win the competition on 16 December 2006, receiving 60% of over eight million televotes cast in the final. As a prize for winning, Lewis signed a £1 million recording contract with Cowell's record label, Syco Music. Upon winning, Lewis said: