Tess Durbeyfield is a 16-year-old simple country girl, the eldest daughter of John and Joan Durbeyfield. In a chance meeting with Parson Tringham along the road one night, John Durbeyfield discovers that he is the descendent of the d'Urbervilles, an ancient, monied family who had land holdings as far back as William the Conqueror in 1066. Upon this discovery, the financially strapped Durbeyfield family learns of a nearby "relative," and John and his wife Joan send Tess to "claim kin" in order to alleviate their impoverished condition. While visiting the d'Urbervilles at The Slopes, Tess meets Alec d'Urberville, who finds himself attracted to Tess. Alec arranges for Tess to become the caretaker for his blind mother's poultry, and Tess moves to The Slopes to take up the position. While in residence at the d'Urbervilles, Alec seduces and rapes Tess.
Tess returns home, gives birth to a son, Sorrow, the product of the rape, and works as a field worker on nearby farms. Sorrow becomes ill and dies in infancy, leaving Tess devastated at her loss. Tess makes another journey away from home to nearby Talbothays Dairy to become a milkmaid to a good-natured dairyman, Mr. Crick. There she meets and falls in love with a travelling farmer's apprentice, Angel Clare. She tries to resist Angel's pleas for her hand in marriage but eventually marries Angel. He does not know Tess' past, although she has tried on several occasions to tell him. After the wedding, Tess and Angel confess their pasts to each other. Tess forgives Angel for his past indiscretions, but Angel cannot forgive Tess for having a child with another man.
Angel suggests that the two split up, with Angel going to Brazil for a year and Tess going back home. Tess agrees and returns to her parent's house. Tess eventually leaves home again for work in another town at Flintcomb-Ash farm, where the working conditions are very harsh. Tess is reunited with some of her friends from Talbothays, and they all settle in at Flintcomb to the hard work routine. Tess is determined to see Angel's family in nearby Emminster but loses her nerve at the last minute. On her return to Flintcomb, Tess sees Alec again, now a practicing evangelical minister, preaching to the folks in the countryside. When Alec sees Tess, he is struck dumb and leaves his position to pursue her. Alec follows her to Flintcomb, asking her to marry him. Tess refuses in the strongest terms, but Alec is persistent.
Tess returns home to find her mother recovering from her illness, but her father, John, dies suddenly from an unknown ailment. The burden of her family's welfare falls on Tess' shoulders. Destitute now and homeless (they have been evicted from their cottage), the Durbeyfields have nowhere to go. Tess knows that she cannot resist Alec's money and the comforts her family can use. Furthermore, Alec insists that Angel will never return and has abandoned her — an idea that Tess has already come to believe herself.
In the meantime, Angel returns from Brazil to look for Tess and to begin his own farm in England. When Angel finds Tess' family, Joan informs him that Tess has gone to Sandbourne, a fashionable seaside resort in the south of England. Angel finds Tess there, living as an upper-class lady with Alec d'Urberville. In the meeting with Angel, Tess asks him to leave and not return for her. Angel does leave, resigned that he had judged Tess too harshly and returned too late.
After her meeting with Angel, Tess confronts Alec and accuses him of lying to her about Angel. In a fit of anger and fury, Tess stabs Alec through the heart with a carving knife, killing him. Tess finds Angel to tell him of the deed. Angel has trouble believing Tess' story but welcomes her back.
The two travel the countryside via back roads to avoid detection. Their plan is to make for a port and leave the country as soon as possible. They spend a week in a vacant house, reunited in bliss for a short time. They are discovered, however, and the trail ends at Stonehenge, the ancient pagan monument, when the police arrest Tess and take her away.
Before she is executed for her crime, Tess has Angel promise to marry her sister Liza Lu once she is gone. Angel agrees and he, along with Liza Lu, witnesses a black flag raised in the city of Wintoncester, signifying that Tess' death sentence has been carried out. The two, Angel and Liza Lu, leave together, and the tragic tale of Tess ends.