North Dakota farmgirl Esther Victoria Blodgett (Janet Gaynor) yearns to become a Hollywood actress. Although her aunt and father discourage such thoughts, Esther’s grandmother (May Robson) gives her 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 (Andy Devine), himself out of work. When Danny and Esther go to a concert to take their minds off their troubles, Esther has her first encounter with Norman Maine (Fredric March), 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’œuvre, she catches Norman’s eye. He gets his longtime producer and good friend, Oliver Niles (Adolphe Menjou), to give her a screen test. Impressed, Oliver gives her a new name (“Vicki Lester”) and a contract. She practices her few lines for her first tiny role.
When the studio has trouble finding a female lead for Norman’s current film, entitled The Enchanted Hour, Norman persuades Oliver to cast Esther. The film makes her an overnight success, even as viewers continue to lose interest in Norman.
Norman proposes to Vicki; she accepts when he promises to give up drinking. They elope without publicity, much to press agent Matt Libby’s (Lionel Stander) disgust, and enjoy a trailer-camping honeymoon in the mountains. When they return, Vicki’s popularity continues to skyrocket, while Norman realizes 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. He starts drinking again. When Vicki wins the industry’s top award, he interrupts her acceptance speech by drunkenly demanding three awards for the worst acting of the year.
A stay at a sanatorium seems to cure Norman’s increasingly disruptive alcoholism, but a chance encounter with Libby gives the press agent an opportunity to vent his long-concealed contempt and dislike for Norman. Norman goes on a four day drinking binge and winds up arrested for drunk driving. In court, the judge sentences him to 60 days of incarceration, but Esther pleads with the judge to put Norman under her care. The judge, who is impressed with Vicki’s acting success, suspends Norman’s sentence and puts Norman’s custody into Vicki’s hands. Vicki decides to give up her career in order to devote herself to his rehabilitation. After Norman overhears her discussing her plan with Oliver, he drowns himself in the Pacific Ocean.
Shattered, Vicki decides to quit and go home. Soon afterward, her grandmother shows up once she hears Vicki is quitting. Her grandmother tells her of a letter Norman sent her when they got married. The letter stated how proud he was of Vicki, and how much he loved her. Because of her grandmother’s words, and the reminder of Norman’s deep love, Vicki is convinced to stay in show business. At the premiere of her next film at Grauman’s Chinese Theatre, when Vicki 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.”