Anna (Audrey Hepburn) is a modern princess on an official visit to Rome. Overwhelmed by her stifling day-to-day life and endless obligations, Anna decides to sneak out one night and explore the city on her own. As she wanders the streets, her path crosses that of Joe Bradley (Gregory Peck), an American journalist who welcomes her into his home. What she doesn’t suspect is that Bradley knows perfectly well that she is a princess, and his goal is to get an exclusive on Anna’s vacation in Rome.
As they enjoy the everyday life of Rome and experience various adventures and embarrassing moments, Bradley and Anna begin to feel closer. In the end they end up falling in love, which puts the young woman in a bind: she must decide between the obligation, the duty that corresponds to her as a princess, and her feelings for Bradley. Will he take the path his heart tells him, or will he succumb to his responsibilities?