The novel opens when a parson casually tells the poor haggler John Durbeyfield that he descends from the noble d'Urbervilles. The idle revelation sets a chain of events going. When the family's horse dies and money runs short, Tess, the eldest daughter, is sent to claim kinship with a wealthy family that has simply bought the old name. There she meets Alec d'Urberville, who pursues her and, on a foggy night in The Chase, takes advantage of her while she sleeps.
Tess returns home pregnant. The child is born, sickens, and dies, and she baptizes it herself when the church will not. Hardy follows her through grief and a slow recovery, refusing to treat her as fallen. She has done nothing that the story counts as guilt, yet the village and her own shame mark her. After a time she leaves to start again where no one knows her.
At Talbothays dairy she finds something like happiness. The work is described with great warmth, and she falls in love with Angel Clare, a thoughtful young man training in farming. They marry. On their wedding night Angel confesses a brief earlier affair, and Tess, taking it as her chance, confesses what happened with Alec. Angel forgives his own past but cannot forgive hers. He leaves for Brazil, and Tess is alone again.
The middle of the book is hardship. Tess takes brutal labor at Flintcomb-Ash through a hard winter, too proud to beg help from Angel's family. Alec reappears, now a would-be preacher, and his old appetite for her returns. As her own family is turned out of their home and her father dies, Tess is worn down by need until she goes back to Alec as his mistress, the only protection left to her.
Angel returns from Brazil, changed and repentant, and finds Tess living with Alec. The recognition that Alec has taken her a second time, after all she suffered, drives Tess to kill him. She and Angel have a few stolen days of peace, sheltering in an empty house and finally at Stonehenge, where she is arrested at dawn. She is hanged. Hardy ends with the line that 'Justice' was done and that the President of the Immortals had ended his sport with Tess, leaving the reader to weigh that bitter irony against everything that came before.