The full title of Moll Flanders gives an apt summary of the plot: "The Fortunes and Misfortunes of the Famous Moll Flanders, Etc. Who was born in Newgate, and during a life of continu'd Variety for Threescore Years, besides her Childhood, was Twelve Year a Whore, five times a Wife (whereof once to her own brother), Twelve Year a Thief, Eight Year a Transported Felon in Virginia, at last grew Rich, liv'd Honest and died a Penitent. Written from her own Memorandums."

Moll Flanders is born to a mother who has been convicted of a felony and who is transported to America soon after her birth. As an infant, Moll lives on public charity, under the care of a kind widow who teaches her manners and needlework. She grows into a beautiful teenager and is seduced at an early age. Abandoned by her first lover, she is compelled to marry his younger brother. He dies after a few years, and she marries a draper who soon flees the country as a fugitive from the law. She marries yet again and moves to America, only to find out that her husband is actually her half-brother. She leaves him in disgust and returns to England, where she becomes the mistress of a man whose wife has gone insane. He renounces his affair with Moll after a religious experience.

Moll's next marriage offer is from a banker whose wife has been cheating on him. Moll agrees to marry him if he can obtain a divorce, and meanwhile she travels to the country and marries a rich gentleman in Lancashire. This man turns out to be a fraud--he is as poor as she is--and they part ways to seek their fortunes separately. Moll returns to marry the banker, who by this time has succeeded in divorcing his wife. He dies soon after, however, and Moll is thrown back upon her own resources once again. She lives in poverty for several years and then begins stealing. She is quite talented at this new "trade" and soon becomes an expert thief and a local legend. Eventually she is caught, imprisoned, and sentenced to death. In prison at Newgate, she reunites with her Lancashire husband, who has also been arrested. They both manage to have their sentences reduced, and they are transported to the colonies, where they begin a new life as plantation owners. In America, Moll rediscovers her brother and her son and claims the inheritance her mother has left her. Prosperous and repentant, she returns with her husband to England at the age of seventy.