The novel opens with a chance encounter between Gabriel Oak and Bathsheba Everdene just outside the town of Casterbridge. Gabriel comes from humble origins as a shepherd, but has recently leased his own farm and seems to have good economic prospects. He is immediately struck by Bathsheba’s beauty, although he quickly becomes aware that she is proud and headstrong. Although Bathsheba has been well-educated, she has fallen on hard times and is now required to take a very hands-on role helping her aunt to take care of her farm. The close proximity of their farms leads to a series of encounters between the two, including an incident in which Bathsheba saves Gabriel’s life.
After only knowing her for a short time, Gabriel proposes to Bathsheba and is surprised when she turns him down, explaining that she does not love him and is reluctant to give up her independence. Shortly after this conversation, Bathsheba moves away to the town of Weatherbury. A short time later, Gabriel experiences a dramatic reversal of fortune when he loses the majority of his sheep in a disastrous accident. He loses all of his money and has to give up his farm and seek work in whatever capacity he can find. While he is looking for work near the town of Weatherbury, he happens to come across a fire that is threatening to destroy a large amount of valuable crops. Gabriel takes charge of the situation and helps to get the fire under control, only to learn later that the owner of the farm is Bathsheba. She has inherited it from her uncle, and has taken the unusual step of managing it herself, even though this was uncommon for a woman at the time. She hires Gabriel to work as a shepherd.
Bathsheba attracts a great deal of attention as an attractive, single, and prosperous woman with unconventional ideas, but she is dismayed to notice that William Boldwood, a successful middle-aged farmer, does not seem curious about her. On a whim, Bathsheba sends him a Valentine’s Day card as a prank; when she does so, she unwittingly sets the stage for Boldwood, who is lonely and shy, to fall deeply in love with her. Boldwood proposes to Bathsheba a short time later, leaving her surprised and uncomfortable. She turns down the offer but is not entirely sure how to proceed in the future, since she knows some aspects of the marriage would be advantageous.
Boldwood's courtship leads to disagreement between Gabriel and Bathsheba, to the point where she initially dismisses him from his job, but quickly hires him back when he saves many of her sheep after they eat poisonous plants and become ill. Boldwood proposes to Bathsheba a second time and although she does not accept, she gives him reason to be hopeful that she will. That same night, however, Bathsheba meets the handsome and charismatic Sergeant Troy, who quickly stirs her emotions. Knowing that Bathsheba is attracted to Troy, whom he is suspicious of, Gabriel encourages her to choose to marry Boldwood instead.
Nonetheless, Bathsheba's growing feelings for Troy lead her to tell Boldwood she can never marry him. Boldwood is angry and jealous, and even threatens violence against Troy, especially since Troy has a bad reputation as a womanizer. Bathsheba is nervous about what will happen when Troy, who is currently away in Bath, returns and she decides to go to Bath herself to end the relationship and tell him not to come back. However, when Troy and Bathsheba return from Bath, they are married, a fact which Troy reveals to Boldwood only after playing a cruel trick on him and deceiving Boldwood into offering to pay Troy to marry the woman he loves. Both Boldwood and Gabriel are deeply upset by this reckless decision.
Their worries seem well-founded, since Troy quickly proves to be lazy and unmotivated to help with running the farm. Gabriel narrowly averts disaster when a severe thunderstorm takes place on the night of the harvest celebrations and he takes the initiative to protect the uncovered crops since everyone else at the farm has gotten too drunk to help out. With Troy showing no signs of wanting to change his behavior, and spending money recklessly, the relationship between him and Bathsheba becomes worse and worse. In October, about 9 months after the beginning of the novel, Troy and Bathsheba meet a young woman walking on the road. She seems to be ill and impoverished, and the sight of her triggers strange behavior from Troy, which he refuses to explain to his wife.
Troy is determined to hide the identity of the woman: Fanny Robbins, who was formerly a servant at the Everdene farm. She and Troy had an affair the previous winter while he was stationed with his troops in Melchester, and Fanny ran away believing she and Troy were going to elope. However, he abandoned her and she found herself pregnant. Now close to giving birth, she is trying to make her way to a local poorhouse. Troy arranges to meet her in a few days time, hoping to give her money and help her. However, after making an agonizing journey to the poorhouse, Fanny and her baby both die during childbirth.
When Bathsheba learns of the death of her former servant, although not the cause, she sends for the body to be brought back to Weatherbury and buried there. Meanwhile, Troy sets out to meet Fanny, unaware of her death. Gabriel arranges for the fact that Fanny died giving birth to be hidden from Bathsheba, but the combination of rumors and her husband's suspicious behavior lead her to open the coffin and find the corpses of both Fanny and the infant inside. Bathsheba also realizes that Troy must be the father of Fanny's child, and when he comes home, the two of them have a heated argument. Bathsheba flees from the house and does not return until the coffin has been taken away. By that time, Troy has also left the house and he is seen leaving town a short time later.
Troy makes his way to the seashore, where he gets caught up in a strong tide while taking a swim. He is rescued by some sailors and impulsively decides to join them on their voyage to America. As a result of this sudden disappearance, Troy is presumed to have drowned, and Bathsheba is declared a widow. This train of events leads Boldwood to hope that he will be able to marry her eventually, although Bathsheba insists that because Troy's death was only established circumstantially, she wants to wait a full 7 years after his death. Time passes, and at the end of the summer, almost a year after his vanishing, Troy secretly returns to Weatherbury. He has gotten tried of living in poverty and is considering reuniting with his wife, although he does not immediately reveal his identity or presence. Meanwhile, Boldwood has mentioned his hopes of marriage to Bathsheba and she has agreed to tell him at Christmas whether or not she will begin the 6-year engagement.
Troy has learned that Bathsheba is considering remarrying, and on Christmas Eve, he makes a surprise appearance at the lavish party Boldwood is throwing. He tries to reclaim Bathsheba as his wife, but Boldwood flies into a rage and shoots and kills him. Boldwood is initially sentenced to death for this crime, but is eventually found to be insane and sentenced to life in prison. Bathsheba is traumatized by these events but slowly recovers, becoming more and more dependent on Gabriel to help her run the farm. She is shocked and unhappy to learn that he plans to leave England and move to America. This news leads Bathsheba to reflect on how valuable and loyal Gabriel has been. One night, she goes to his cottage to ask him why he is determined to leave, and as the two talk, it becomes clear that they both love each other, but have each been confused about the feelings of the other. A short time later, Gabriel and Bathsheba finally marry with much rejoicing from the local people and farm workers.
