The novel is set in 1959 at the prestigious Welton Academy, a Vermont boarding school. As the school year begins, we meet Todd Anderson, a shy new student who’s transferred from another school, as well as Neil Perry, Richard Cameron, and Charlie Dalton—all junior-year students. Neil Perry is a likable, kind student, and is Todd’s roommate; Neil is terrified of his own father, Mr. Perry, who insists that Neil must study chemistry, go to Harvard, and become a doctor. Richard Cameron is an uptight, conforming student who hates breaking rules; Charlie Dalton, on the other hand, is an easygoing, rebellious student who loves breaking rules.
Another Welton student and friend of Neil’s, Knox Overstreet, goes to have dinner with some family friends, the Danburrys. During dinner, he meets Chris Noel, the beautiful girlfriend of Chet Danburry, the Danburrys’ son. Knox is instantly smitten, but doesn’t know what to do about his love.
Classes begin at Welton. Most of the teachers are extremely rigorous and controlling. However, there’s a new English teacher at school, John Keating, who is different. Keating immediately impresses his students with his charismatic, energetic lectures—in the first of which he stands on his desk. While other teachers force students to do homework and obey them at all times, Keating begins the year by talking about “Carpe Diem,” the idea that humans should “seize the day”—i.e., make the most of life while they’re alive. This year, Keating promises, he wants to teach his students how to be extraordinary instead of simply following the rules. Keating’s unusual teaching methods draw some attention from his colleagues, but because he’s an intelligent, likable man, he stays in the good graces of the Welton headmaster, Gale Nolan.
Neil tries to engage with Todd and become his friend, but Todd is too shy and reserved. Things begin to change when Neil comes across an old yearbook in which he learns that John Keating was once a student at Welton; during that time, Keating was a member of a club called the Dead Poets Society. When Neil and his friends ask Keating about the Dead Poets, Keating explains that the Dead Poets met in a cave near Welton, read poetry, and celebrated life. Later, Neil finds that someone, presumably Keating, has put an old poetry anthology marked “Dead Poets” in his room. Neil convinces his friends, including Knox, Cameron, Charlie, and Todd, to go to the cave, and together they read from the poetry anthology, gradually becoming transfixed by the poems’ beauty.
In class, Keating asks his students to compose poems. Todd is at first unable to write anything that he feels comfortable reading in from of the other students, but with Keating’s encouragement, he improvises a brilliant poem about Keating’s hero, Walt Whitman. Afterwards, Todd begins to open up, both with his classmates and with Keating. He admits to Neil that he feels that his parents don’t love him—they’re incredibly hard on him, and clearly prefer his older sibling. Neil is sympathetic to Todd’s problems, since they echo his own. Keating’s lessons also inspire Neil to try out for a local production of A Midsummer Night’s Dream–to his delight, he gets the lead part of Puck.
The students’ attempts to “seize the day,” inspired by Keating, become increasingly reckless and foolish. Charlie Dalton pens an article in the school paper in which he claims that women should be admitted to Welton, and signs it “The Dead Poets.” To protect his classmates, Charlie comes forward and admits he wrote the article—he’s given corporal punishment by Nolan, but doesn’t tell Nolan anything about the Dead Poets Society. Meanwhile, Knox is invited to a party with Chris and Chet—at the party, he gets very drunk and, telling himself that he’s just “seizing the day,” he touches Chris’s breasts, infuriating Chet. In response to his students’ wild actions, and the suspicion he’s been getting from Nolan, Keating tries to teach his students how to be realistic, “survive” college, and bluff their ways through essays about horrible books that aren’t worth reading.
Mr. Perry finds out that Neil is going to be in A Midsummer Night’s Dream, and furiously forbids him from performing in the play. Neil, unsure what to do, goes to Keating for advice. Keating advises Neil to talk to his father and show him how passionate he is about acting. Neil can’t bring himself to talk to his father, but tells Keating that Mr. Perry gave him permission to perform after all.
Knox goes to Chris’s school and reads her a poem he wrote for her, in which he professes his love. Later, Chris visits Knox at Welton and warns him that Chet is going to kill him for what he’s done. Knox begs Chris to go see A Midsummer Night’s Dream with him—if she doesn’t have a good time, he’ll never try to see her again. Reluctantly, Chris agrees.
Chris, Knox, Keating, and the other Dead Poets go to see Neil in A Midsummer Night’s Dream. Neil is spectacular as Puck, to everyone’s delight, especially Todd. Chris begins to develop feelings for Knox during the performance—and later that night, she kisses Knox. After the show, however, Mr. Perry appears to confront Neil. He brings Neil home and tells him that he’ll be going to a rigorous military academy from now on—clearly, Welton is distracting him from his “goals” of being a doctor. Neil is so upset by this news that, late at night, he shoots himself with his father’s revolver.
In the aftermath of Neil’s suicide, there’s an investigation, at Mr. Perry’s request, into the matter. Cameron betrays the Dead Poets by going to Nolan and telling him about the Dead Poets Society. Nolan uses Cameron’s information to cast Keating as a scapegoat—by blaming Keating for “corrupting” Neil with talk of freedom and individuality, Nolan hopes to avoid a full-scale scandal with Welton’s wealthy alumni donors.
One by one, the students are brought into Nolan’s office and forced to sign a document stating that Keating corrupted them with his free-thinking lessons, and thereby compelled Neil to commit suicide. While most of the Dead Poets sign the document, Todd refuses to do so—and Nolan places him under strict probation for refusing to go along. In spite of Todd’s loyalty, Keating is fired from Welton and essentially barred from ever teaching again.
In the final chapter, the students file into English class, now being taught by the dull Headmaster Nolan himself. In the middle of the lesson, Keating walks in to pick up his personal items. While Keating gathers his things, Todd runs up to him, explaining that Nolan forced the students to sign the document that’s gotten Keating fired. Keating smiles and nods, showing that he understands. Todd stands on his desk, just as Keating did during his first lesson at Welton. Slowly, and despite Nolan’s cries to stop, the other students join Todd in an inspiring show of solidarity with Keating.