Farm girl Esther Victoria Blodgett yearns to become a Hollywood actress. Although her aunt and father discourage such thoughts, Esther’s grandmother gives Esther her savings to follow her dream.

Esther goes to Hollywood and tries to land a job as an extra, but so many others have had the same idea that the casting agency has stopped accepting applications. Esther is told that her chances of becoming a star are one in 100,000. She befriends a new resident at her boarding house, assistant director Danny McGuire, himself out of work. When Danny and Esther go to a concert to celebrate Danny’s employment, Esther has her first encounter with Norman Maine, an actor she admires greatly. Norman has been a major star for years, but his alcoholism has sent his career into a downward spiral.

Danny gets Esther a one-time waitressing job at a fancy Hollywood party. While serving hors d’œuvres, she catches Norman’s eye. The next day, he gets his longtime producer and good friend, Oliver Niles, to give her a screen test. Impressed, Oliver gives her a contract and a new name, “Vicki Lester”. She practices her few lines for her first tiny role.

When the studio has trouble finding a female lead for Norman’s current film, titled The Enchanted Hour, Norman persuades Oliver to cast Esther. The film makes her an overnight success, even as cinemagoers and exhibitors continue to lose interest in Norman.

Norman proposes to Esther; she accepts when he promises to give up drinking. They elope without publicity, much to press agent Matt Libby’s disgust, and enjoy a trailer-camping honeymoon in the mountains. When they return, Esther’s popularity continues to skyrocket, and Norman realizes that his own career is over despite Oliver’s attempts to help him.

Norman stays sober for a while, but his frustration over his situation finally pushes him over the edge, and he starts drinking again. When Esther wins the industry’s top award (the Academy Award for Best Actress), he interrupts her acceptance speech by drunkenly demanding three awards for the worst acting of the year and accidentally slapping her when he dramatically swings his arms back.

A stay at a sanatorium seems to cure Norman’s increasingly disruptive alcoholism, but a chance encounter with Libby allows the press agent to vent his long-concealed contempt. Norman goes on a four-day drinking binge, and he is arrested for drunk driving. In court, the judge sentences him to 90 days of incarceration, but Esther pleads with the judge to put Norman under her care. The judge, who is impressed with Esther’s acting success, suspends Norman’s sentence and puts Norman’s custody into Esther’s hands. Esther decides to give up her career to devote herself to his rehabilitation. After Norman overhears her discussing her plan with Oliver, he drowns himself in the Pacific Ocean.

Shattered, Esther decides to quit and go home. Showing up soon afterward is her grandmother, who has heard that Esther is quitting. Her grandmother tells her of a letter Norman sent her when they got married. The letter stated how proud he was of Esther and how much he loved her. Because of her grandmother’s words and the reminder of Norman’s deep love, Esther is convinced to stay in show business. At the premiere of her next film at Grauman’s Chinese Theatre, when Esther is asked to say a few words into the microphone to her many fans listening across the world, she announces “Hello, everybody. This is Mrs. Norman Maine.”