It is 1960, and a chorus of young girls energetically sings the praises of rock & roll idol Conrad Birdie. At Almelou Music Corp. in New York, Conrad’s managers, Albert Peterson and Rosie Alvarez (who’ve been dating for years), learn that their client has been inducted into the army. Though she’d prefer that Albert settle down and become “An English Teacher,” Rosie concocts a plan: as a publicity stunt, Conrad will bid a typical American teen-age girl goodbye with a public farewell kiss. Rosie randomly selects the name of the lucky girl: fifteen-year-old Kim McAfee of Sweet Apple, Ohio.
Meanwhile, in Sweet Apple, every teenager in town is on the phone, gossiping about Kim and her new steady, Hugo Peabody (“The Telephone Hour”). Kim, who proudly celebrates her new maturity (“How Lovely To Be A Woman”), is astonished to hear the news about Birdie.
In New York’s Penn Station, Albert cheers up a downcast Birdie fan (“Put On A Happy Face”). Mae, Albert’s overbearing mother, insults Rose, but Albert is unable to stand up to her. Birdie arrives, pursued by reporters, so Albert and Rosie deftly manage the press (“Healthy Normal American Boy”).
In Sweet Apple, Hugo is a bit jealous of the attention Kim pays to Birdie, but Kim assures Hugo he is the “One Boy” for her. On the courthouse steps, the Mayor welcomes Conrad, who bowls everyone over with his powerhouse hit, “Honestly Sincere.”
With Conrad staying for the week, the McAfee household is completely turned upside down. A frustrated Mr. McAfee threatens to put his foot down, until he hears the family will be appearing on The Ed Sullivan Show (“Hymn For A Sunday Evening”). Mae, who followed Albert and Rosie by bus, introduces Albert to a sensational tap-dancer named Gloria Rasputin, whom Albert begrudgingly hires as a typist. Rosie, enraged by Albert’s behavior, enlists the aide of Hugo in a plan to undermine the big show. On The Ed Sullivan Show, Conrad prepares to give Kim “One Last Kiss,” but at the last minute, Hugo steps onstage and punches Conrad, knocking him to the floor. Everyone scatters, and Rosie bids Albert a bitter farewell, leaving him alone on national television. Smiling nervously, Albert desperately tries to recover (“Healthy Normal American Boy” Reprise).
Rosie and Kim, furious at Albert and Hugo, pack up to leave (“What Did I Ever See In Him?”). Albert and Mae make a new plan: Conrad will now kiss Kim at the train station before he leaves. But Conrad is tired of being locked up in a suburban household, and he invites the kids to join him in a wild night out (“A Lot of Livin’ To Do”). Mr. and Mrs. McAfee, fearing the worst, join up with other parents to find their teens (“Kids!”). Mae continues to pester Albert and berate Rosie. Finally, Albert stands up to his mother, demanding that she go home.
At the Ice House, a popular spot for teens, Kim tries to ward off Conrad’s advances. The parents and Hugo arrive just in time, and Kim realises that she belongs with Hugo. Rosie and Albert make up, too, and Rosie has a bit of fun mocking Mae. The next morning, Albert sneaks Conrad out of town and tells Rose he’s accepted a teaching job in Pumpkin Falls, Iowa. Albert and Rose celebrate their new future (“Rosie”) and dance off into the sunset.