Kelly Brook was born in Rochester, Kent, England(born as Kelly Ann Parsons; 23 November 1979).
She is the daughter of Sandra, a cook, and Ken, a scaffolder, she has a younger brother, Damian, and an older half-sister named Sasha. Ken Parsons died from cancer on 26 November 2007, during Brook's time on Strictly Come Dancing.
Brook attended The Thomas Aveling School in Warren Wood, Rochester, Kent. She then studied at the Italia Conti Academy of Theatre Arts in London for three years before becoming a professional model. Brook's modelling career began at 16 after winning a beauty competition, in which she was entered by her mother. She later 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 figure eventually caught the eye of the editorial team of the Daily Star tabloid, which began featuring her as a Page Three girl.