The Hours follows three women through one day in their lives. One of the narrative strands explores the day in 1923 when Virginia Woolf begins to write Mrs. Dalloway. Another centers around a day in the life of Laura Brown, an American housewife, in 1949, in which she spends part of her time reading Mrs. Dalloway. The third narrative takes place on a day in the late twentieth century, in which Clarissa Vaughn hosts a party for her poet-friend Richard. The chapters alternate with rough regularity between these three main characters.

The prologue details the suicide of Virginia Woolf. She leaves notes for her husband and sister, then walks to a nearby river. She selects a large stone from the bank, places it her pocket, and wades into the water.

The next group of chapters retells the early mornings of the three main characters. Clarissa Vaughn leaves her New York apartment to buy flowers. She is hosting a party that evening in honor of her best friend Richard, a poet and novelist dying of AIDS, who is receiving a prestigious literary award for his life’s work. As she walks, she bumps into her old friend Walter Hardy and catches a glimpse of a movie star peeking outside of her trailer.

The story turns to Virginia Woolf on a morning nearly twenty years before she commits suicide. She wakes up thinking about how to begin her new novel, which will detail a day in the life of a woman named Clarissa Dalloway. Virginia greets her husband as he corrects proofs, and she skips breakfast to avoid dealing with her temperamental cook. After returning to her room, she settles in to write.

The attention turns to Laura Brown, a mother living in Los Angeles after World War II as she lies in bed reading Mrs. Dalloway. She does not have the energy to go downstairs and say “happy birthday” to her husband, Dan, or to make breakfast for her young son, Richie. After reading for an hour or two, she finally goes downstairs. Dan leaves for work and she is alone with her son.

In what is now late morning, Clarissa Vaughn stands on the street outside the flower shop trying to catch sight of the movie star who came out of the trailer. She gives up and continues walking, passing the corner where she and Richard broke up many years ago. She visits Richard in his messy apartment, brightening the kitchen with fresh flowers as she asks about his health. They must go uptown that night to collect his prize and then go to the party, but despite Clarissa’s reassurances, Richard protests that he does not deserve the prize.

Virginia Woolf feels the first strains of a crippling headache and sets down her pen after writing for two hours. Because of her health, Leonard has moved her from London to the suburbs, even though she desperately wants to return to the city. Virginia finds Leonard in the printing room chastising his assistant, and she smoothes over the argument. Laura Brown bakes a birthday cake with her son’s help, deciding that the cake must be a perfect work of art.

Before lunch, Virginia takes a walk and thinks about her character Clarissa Dalloway. She decides that Clarissa will have once been in love with a woman and that she will kill herself. Upon returning to the house, she speaks to her cook, who has become angry with Virginia for not organizing lunch. The situation worsens when the cook finds out that Virginia’s sister Vanessa will be bringing her family for tea that afternoon, and the cook must commute to London to pick up special ingredients.

Clarissa Vaughn bumps into her live-in lover Sally on the way back to their apartment. Sally plans to have lunch with a movie-star friend of hers. As Clarissa puts flowers into water, she thinks about her disappointment over not getting an invitation to this lunch. She feels alienated from her own house and her life, and reminisces about the happy summer she spent with Richard in Wellfleet when they were still romantically involved. Clarissa thinks that summer may have been the only perfect time in her life. Laura Brown finishes the cake and feels disappointed that it does not attain the standard of perfection she had hoped for. Her neighbor Kitty stops by to tell Laura that she must enter the hospital for tests on her uterus. The two women embrace and kiss momentarily, an experience that moves Laura.

After lunch, Vanessa Bell surprises her sister Virginia by arriving early for tea. Vanessa’s three children find a dying bird in the garden and make a grass bed for the bird with Virginia’s help. Clarissa Vaughn receives a visit from her old friend Louis at her apartment. A former lover of Richard’s who lived with them at Wellfleet, Louis now teaches in San Francisco and has begun an affair with a young student. As they talk, Clarissa’s rebellious daughter Julia shows up at the apartment, and Louis leaves. Laura Brown has thrown away the first cake and baked another. Bored, she feels the need to escape and leaves Richie at a neighbor’s house. She checks into a hotel to read Mrs. Dalloway for two hours, thinking about the concept of suicide and deciding that she could never kill herself.

In the mid-afternoon, Vanessa and Virginia sit in the kitchen drinking tea. Virginia feels happy and decides that Clarissa Dalloway will not commit suicide after all. Nelly storms in from London, and when she turns her back, Virginia leans in and kisses her sister on the lips. Meanwhile, Clarissa chats with her daughter, Julia, who has brought her difficult friend Mary Krull to the apartment. Clarissa clashes with Mary, who finally leaves to go shopping with Julia.

Virginia Woolf feels depressed after her sister leaves and attempts to write but decides to take a walk to clear her head. After passing the dead bird in the garden, she wanders to the train station, where she contemplates taking a train to London. As she waits, Leonard shows up and brings her back to the house. The story turns to Clarissa’s lover, Sally, as she eats lunch with Walter Hardy and Oliver St. Ives, the movie star. After lunch, Sally shops with Walter as he buys a gift for his lover, which prompts Sally to stop and buy roses for Clarissa on the way home.

Before dinner, Laura drives back to the babysitter’s house to pick up her son. Clarissa Vaughn goes over to Richard’s apartment to pick him up for the party to find him sitting on the windowsill. He tells her he loves her and jumps out of the window to his death. Laura Brown watches her husband and her son eat the cake that she has made and thinks about her dissatisfaction with her picture-perfect life.

The last group of chapters follows the women as they prepare for bed. Virginia Woolf has convinced Leonard to move back to London. She thinks of the kiss she shared with Vanessa and decides that Clarissa Dalloway will have shared a similar kiss with a lover when she was young. After some thought, she decides that Clarissa will not commit suicide, but that someone insane and sensitive will do so instead. Laura Brown gazes into the mirror as she brushes her teeth. Detached from her body, she thinks about the fact that Dan will want to have sex with her. In the final chapter, an older Laura comes to stay at Clarissa’s apartment in the wake of her son Richard’s death. After they speak, Clarissa reflects on the meaning of the passage of time.