The first of the four narrators of the "120 Days of Sodom" and the only one whose story is fully completed by Sade in the draft of the novel. Led into a life of prostitution as a young girl by her older sister, Duclos lives her entire life in a brothel, eventually taking it over herself when she poisons the original owner. Duclos provides the four friends with 150 examples of the "simple" passions of sexual behavior. She is held in high regard among the friends for her life of depravity and criminality and is one of the select few who are allowed to survive the orgy.