Biography: Holly Madison (born Holly Sue Cullen; December 23, 1979) is an American television personality, best known as a former girlfriend of Hugh Hefner and for her appearance in the reality television show The Girls Next Door. She also starred in her own reality series, Holly's World, which ran from 2009 to 2011. She has released two books, Down the Rabbit Hole: Curious Adventures and Cautionary Tales of a Former Playboy Bunny in 2015, about her life in the Playboy Mansion and her relationship with Hefner, and The Vegas Diaries: Romance, Rolling the Dice, and the Road to Reinvention in 2016.