The Bell Jar is Sylvia Plath's only novel, which was originally published under the pseudonym Victoria Lucas. The novel is autobiographical, with the names of places and people changed to avoid causing offence. After Plath's suicide, the novel was published under her real name, and the novel did cause great offense. This resulted in a successful lawsuit by one individual (who is portrayed as "Jean" in the book), where the court ruled that the novel unfairly branded her a homosexual.

The protagonist, Esther Greenwood, gains a scholarship in New York to work at a prominent magazine, at the time of the Rosenbergs' execution. Esther makes friends with Doreen, and although she thinks that Doreen is a "dirty common slag", Esther attempts to be like her in every way, attempting to lose her virginity at every opportunity, which becomes an unhealthy obsession. She also finds a patron in Philomena Guinea, who was based on Plath's own patron, Olive Higgins Prouty, author of Stella Dallas and Now, Voyager. Plath's real-life magazine scholarship was at Mademoiselle magazine, which became defunct in November, 2001. Esther has a boyfriend, Buddy Willard, who is diagnosed with tuberculosis and is sent to a sanatorium. Esther struggles to cope with life in New York and moves back to live with her mother, who she believes was in part responsible for the death of her father, who was a diabetic. She becomes addicted to sleeping pills, and is sent to see a psychiatrist. She is then sent to a mental hospital, making new friends along the way, and is subjected to intense electric shock therapy. Esther does not lose her virginity until chapter nineteen, near the end of the book, and she suffers immense bleeding and is admitted to a hospital.

The book is full of irony, especially in comparison to Plath's life. Esther continually makes reference to her hatred of children and how she would never have any, but Sylvia Plath did in fact have children with the English poet Ted Hughes. There are also connections between Plath's life and the Rosenbergs. Plath was subjected to electric shock therapy, and the Rosenbergs were executed in the electric chair; when she committed suicide, she left her two children behind, as did the Rosenbergs.

Some critics have likened the book to a female version of The Catcher in the Rye by J.D. Salinger.