The story is about a young princess (公主) (Hepburn) named Ann, making a goodwill (善意的) tour of Europe's capitals. She is tired of the responsibility (职责) and demands of the role she has been born in to and longs to experience the every day pleasures of an ordinary person. In Rome she finally rebels. Waiting until after everyone in the embassy (大使馆) where her party is staying has gone to sleep, she slips out a window and finds herself alone on the streets of Rome.

　　 She is found by Joe Bradley (Peck), a hardened (坚毅的) and somewhat cynical (愤世嫉俗的) reporter, on his way home from a late night card game. Not knowing who she is but seeing that she has no place to stay he takes pity on her and invites her to his apartment for the night. In a comical (滑稽的) scene, he offers her a pair of his pajamas (睡衣) and points to the couch where she can sleep. Innocent (天真的) aristocrat (贵族) that she is, she asks for a nightgown and help undressing. Bradley helps her take off her tie and then leaves the room. When he returns a few minutes later he discovers her sound asleep on the bed, leaving him the couch (沙发).

　　 Leaving her sleeping the next morning, Bradley shows up late for work and tries to cover himself by saying that he had an interview (采访) with the princess. But his editor shows him a newspaper with her picture and headline stating that she was taken ill the night before and canceled all appointments (安排) for the day. Bradley immediately realizes who he has in his apartment and gets the editor to agree to pay $5,000 if he can get a real interview with the princess. On the way out Bradley contacts a photographer (摄影师) friend, Irving Radovich (Albert) and arranges for him to met him later with his camera for a big scoop.

　　 Returning to his apartment, Bradley picks up the princess for their planned tour of the city. Bradley's real aim is to get the pictures and story he promised (答应) his editor. But the innocent charm of the princess softens him and the two start to fall in love. They end up having a good time and some comical adventures (冒险). Bradley conceals the fact that he is a reporter who knows who she really is and she doesn't tell him that that she is a royal princess. But in the end the truth comes out and the princess realizes that her duty to her country and family come first and she reluctantly (不情愿地) returns to her official role.

　　 The two meet briefly at the end during her press conference with other reporters. She addresses Bradley as Mr. Bradley just like the others. As he is leaving, Bradley, quietly slips her the photos that his friend Irving had taken and lets her know that his story and pictures of their time together will never be published (公布).

　　 The charming Audrey Hepburn plays a modern princess who takes a day on Rome. She meets up with reporter Peck and wise-cracking photographer Albert. Peck and Hepburn fall in love, though Peck plans to sell an "exclusive story with the princess." Roman Holiday is a fun romantic comedy, but stays realistic (现实) with its commentary on society and royalty.