At 16 years of age, Hazell left school to work as a hairdresser. Her work colleagues persuaded her to try her luck at modelling. At 17, she competed in The Daily Star's "Search for a Beach Babe" contest and won. Still not old enough to pose on Page 3, she went to study fashion at Lewisham College.But later, a friend told her about The Sun's Page 3 Idol competition. Despite some initial uncertainty about entering the contest, she submitted some photos. She was eventually chosen the winner in December 2004. She won £10,000 worth of "sexy clothes" and "a one-year membership of the Rex cinema and bar". Another part of Hazell's Page 3 Idol win was a one-year exclusive glamour modelling contract with The Sun.
Hazell was regularly featured in Nuts and Zoo. She has been on the cover of The Sun's 2006 and 2007 Page 3 calendars, in addition to her own wall calendars, the 2007 edition selling 30,000 copies in its first few days of release.
In 2008, Hazell and agent Ginny Mettrick co-founded a modelling agency called Muse Management.
In 2009, according to the August edition of Loaded, Peta Todd states that Keeley has given modelling up to pursue a career in acting and was in America receiving acting lessons. Her last appearance on Page 3 of The Sun was on 30 September 2009.