Born Kelly Parsons on November 23, 1979, in Rochester, Kent, England, she is the daughter of Sandra, a cook, and Ken, a scaffolder. Ken Parsons died from cancer in November 2007, during Brook's time on Strictly Come Dancing.
Kelly attended The Thomas Aveling School in Warren Wood, Rochester, Kent. After leaving school in Rochester, Brook studied at the Italia Conti stage school in London for three years before becoming a professional model.
Brook's modelling career began at 16 after winning a beauty competition her mother entered her in. Following this success she worked on a range of advertising campaigns, including for Foster's Lager, Renault Megane, Walkers crisps, Piz Buin and Bravissimo, a company that specialises in bras and lingerie for large-breasted women. Her voluptuous figure eventually caught the eye of the editorial team of the Daily Star tabloid, which began featuring her as a Page Three girl.
Brook's picture soon began appearing in other lad mags such as GQ, Loaded and FHM. In April of the same year a poll over 5,000 women for Grazia magazine considered her to have the best British female body. She also topped the 'FHM 100 Sexiest Women in the World' list in 2005, which was said to have polled 15 million people. She later ranked 5th in FHM's '100 Sexiest Women in the World 2006', 17th in 2007 and 34th in 2008 respectively.
Brook has also done a large amount of commercial swimwear, sportswear and hosiery modeling. Her work for Triumph Bras caused quite a stir because of specially-commissioned 50-foot (15 m) high billboards of Brook's bust, said to be the largest billboards in the world.
In 2005, Brook posed for a ten-page, partially-nude black-and-white photo spread with the photographer David Bailey. The results were featured in the British design magazine Arena, the November 2005 issue.
In 2006 she signed a contract, reported to be worth around £1m, to be the presenter of Unilever's Lynx body spray, known as Axe in the US and on continental Europe. She has appeared on billboards, in newspapers, and on-line as part of an advertising campaign.
She has also appeared in commercials for Sky + and most recently T Mobile.
In 2006, she introduced a range of self-designed swimwear and lingerie at New Look stores in the United Kingdom. She also modeled the range in a number of provocative television and magazines adverts.
