Stoner begins with a prologue which is the obituary of William Stoner, the protagonist himself. The author, removes all elements of suspense and surprise, revealing the fate of titular protagonist William Stoner as the novel begins. Stoner dies an ordinary professor of English literature whose singular contribution was a manuscript donated to the University in his name after his death.
Born in Missouri to poor farmers, his parents send him to the University of Missouri to study Agrarian Sciences. At University Stoner is unmotivated and lost and has no interest in what he is studying until he takes a compulsory English literature class. The professor, Archer Sloane, asks Stoner to analyse Shakespeare's Sonnet 73. Put on the spot, Stoner transcends to the world of words whilst he tries to analyse the sonnet. After this experience Stoner realizes that his true calling is literature, he switches his major to English Literature and is taken under the wing of Archer Sloane. His parents however only find out that he is not coming back to farm on the day of his graduation.
After graduating college, Stoner completes his masters degree and begins to teach English literature. However, he is not as great a teacher as he was a student. All of Stoner's friends and classmates from graduate school enlist to fight in the First World War, but Stoner does not enlist and faces some criticism for this.
The war ends and the United States signs the Armistice. Stoner meets Edith, a cold and reserved woman. Propelled by his romantic notions, Stoner pursues Edith, convinced that he can wear her defenses down. Edith, however, is an emotionally damaged woman who was raised to be shrewd, calculating, and sexually repressed. Stoner and Edith marry after a short courtship with the permission of Edith's parents. Stoner becomes distanced from his own family because they are considered to crude and unrefined by Edith's family.
Their marriage is far from happy. Edith makes their house a toxic environment, withholding sex and constantly fighting. Stoner begins to spend more time at work than in his home. Edith expresses her desire for a child three years after their marriage, she suddenly displays a surge of sexual interest towards this end. However, as soon as Grace, their daughter, is born this interest significantly decreases. Edith spends a year in bed suffering from an unknown illness after the birth of Grace. she notices that Grace and Stoner have a strong bond and goes to considerable lengths to destroy their relationship.
Adjacently, Stoner is given tenure at his University and is promoted to the position of assistant professor. On an assignment Stoner fails his student Charles Walker. Walker, a disabled student was especially known for his gift of gab that shrouds his lack of knowledge. Stoner's grade for Walker pushes him into office politics because Walker is the charge of Hollis Lomaz, a renowned professor at their university who is also disabled. Stoner is accused to be biased against students who are disabled and Lomax launches a campaign to destroy Stoner's career at the University.
Stoner meets Katherine Driscoll, a young new professor. The two fall in love and have a torrid affair. Stoner is happiest in this part of his life. When Edith learns about his affair she is unconcerned. However, when Lomax finds out about their relationship he uses his power and intimidates Katherine into ending the affair. Katherine leaves the University and the town. Stoner never sees her again.
After Katherine leaves, Stoner is lost and retreats into himself. Edith continues to abuse and torment both Grace and Stoner, now Grace more than Stoner because of Grace's weight. Grace attends the University of Missouri because of her mother's insistence, and there she becomes pregnant and quickly marries the father of her baby. Grace drops out of college and her husband is killed in the Second World War.
Stoner finds that he has cancer just as his mandatory retirement age comes close. He leaves the University. As he ruminates on his life, he realizes that although he faced many obstacles and his life was largely average, his relationship with literature and books are what gave it meaning. The book ends as Stoner passes with his hand on the first copy of his book.
