Set in Jackson, Mississippi, the novel begins in August 1962 with Aibileen Clark, a middle-aged black domestic worker, taking care of Elizabeth Leefolt’s only child, Mae Mobley. Miss Leefolt, a white housewife, neglects her daughter, but Aibileen showers Mae Mobley with affection. The novel opens with a luncheon at Leefolt’s house where the 23-year-old white women Hilly Holbrook and Eugenia “Skeeter” Phelan discuss Hilly’s initiative to pass a bill that would require every white household to have a separate bathroom for black housemaids. Disgusted by Hilly’s idea, Skeeter finds Aibileen and asks if she ever wished she could change things. Unwilling to express her true feelings to a white woman, Aibileen says that everything is fine.
A few days later, Minny Jackson, another black maid and Aibileen’s best friend, loses her job working for Hilly’s mother. Hilly has also spread rumors about Minny being a thief so none of the other neighbors will hire her. Minny tells Aibileen that she took revenge on Hilly, but she won’t give her the details, only telling her that it involved a pie. Minny ultimately finds work with the white housewife Celia Foote, a woman none of the white housewives in the community befriends because she comes from a working class background. Celia is kind to Minny and does not treat her any differently for being black.
Meanwhile, Skeeter gets a job writing an advice column about housekeeping for the Jackson Journal. Since she knows nothing about cleaning or cooking, she goes to her friend Elizabeth Leefolt’s house to ask Aibileen, her maid, some questions. While interviewing her, Skeeter learns that Aibileen’s recently deceased son had been writing a book on his experiences working for white men in Mississippi. Seeing firsthand how her friends treat their maids, Skeeter, who wants to be a writer herself, gets the idea to interview Aibileen about her experiences for a book about black domestic workers in the South.
At first, Aibileen declines to be interviewed for fear of losing her job or being targeted by white racists for publically criticizing white women. Aibileen changes her mind in order to help stop the racism that people like Miss Hilly are perpetuating in Jackson. Minny also tells her stories to Skeeter, but all the other maids in the community are too scared to talk. Skeeter also steals a book on the Jim Crow laws, which Hilly unluckily finds in her satchel. Thinking that Skeeter may be a secret integrationist, Hilly distances herself from her and tells the other women in the community to shun her.
Hilly’s maid, Yule May, steals a ring from Hilly so that she can afford to put her twins through college. Yule had originally asked Hilly for a loan before stealing the ring, but Hilly had refused. Despite the fact that Yule May was a loyal maid for so many years, Hilly uses her influence to have Yule thrown in jail overnight. Seething with anger at the injustice, the other maids agree to contribute their stories to Skeeter’s book.
When the book is nearly complete, Skeeter starts to worry that the maid’s pseudonyms won’t be enough to stop the Jackson housewives from figuring out that the book is about them. Minny decides to tell Aibileen and Skeeter about what she did to Hilly as “protection.” As revenge for ruining her chances of finding work, Minny baked Hilly a pie with her own feces in it and fed it to her. When Hilly reads this story in the book, she’ll know for sure that the book is about Jackson, but she’ll also use her influence to steer people away from coming to the same conclusion about the setting so that she can protect herself from the humiliation of people finding out that she ate a black woman’s excrement pie.
When the book gets published, people in Jackson start to realize the book is about them, but Minny’s plan works and Hilly tries to convince them otherwise. Skeeter ends up accepting a job as an editorial assistant in New York and, after a tearful goodbye with Aibileen, picks up and goes. Hilly, however, still tries to take revenge on the maids. Figuring out that Aibileen must have had a role in the project, Hilly has Elizabeth fire her. Even so, Aibileen, who has taken over Skeeter’s job writing the housekeeping column for the Jackson Journal, leaves Miss Leefolt’s house feeling unburdened and free now that she’s told the stories. The book ends with Aibileen feeling ready to write more about her life and experiences.