Gelsomina (Giulietta Masina), a young woman, learns that her sister Rosa has died after going on the road with the strongman Zampanò (Anthony Quinn). Now the man has returned a year later to ask her mother if Gelsomina will take Rosa’s place. The mother accepts 10,000 lire, and her daughter departs the same day.
Zampanò makes his living as an itinerant street performer, entertaining crowds by breaking an iron chain bound tightly across his chest, then passing the hat for tips. In short order, Gelsomina’s naïve and antic nature emerges, with Zampanò’s brutish methods presenting a callous foil. He teaches her to play the snare drum and trumpet, dance a bit, and clown for the audience. Despite her willingness to please, he intimidates her and treats her cruelly at times.
Finally, she rebels and leaves, making her way into town. There she watches the act of another street entertainer, Il Matto (“The Fool”), a talented high wire artist and clown (Richard Basehart). When Zampanò finds her there, he forcibly takes her back. They join a ragtag travelling circus where Il Matto already works. Il Matto teases the strongman at every opportunity, though he cannot explain what motivates him to do so. After Il Matto drenches Zampanò with a pail of water, Zampanò chases after his tormentor with his knife drawn. As a result, he is briefly jailed, and both men are fired from the travelling circus.
Before Zampanò’s release from prison, Il Matto proposes that there are alternatives to Gelsomina’s servitude, and imparts his philosophy that everything and everyone has a purpose – even a pebble, even she. A nun suggests that Gelsomina’s purpose in life is comparable to her own. But when Gelsomina offers Zampanò marriage, he brushes her off.
On an empty stretch of road, Zampanò comes upon Il Matto fixing a flat tire. As Gelsomina watches in horror, the strongman strikes the clown on the head several times. Il Matto complains that his watch is broken, then collapses and dies. Zampanò hides the body and pushes the car off the road, where it bursts into flames.
The killing breaks Gelsomina’s spirit and she becomes apathetic. Finally Zampanò abandons her while she is taking a nap, leaving some clothes, money, and his trumpet.
Some years later, he overhears a woman singing a tune Gelsomina often played. He learns that the woman’s father had found Gelsomina on the beach and kindly taken her in. However, she had wasted away and died. Zampanò gets drunk and wanders to the beach, where he breaks down in tears.