Easter dawns in a Sicilian village. Turiddu is heard in the distance singing about Lola, wife of the prosperous carter Alfio (“O Lola, bianca come fior di spino”). Townsfolk and fieldworkers mingle in the piazza, then disperse. Santuzza approaches Mamma Lucia’s tavern looking for her son Turiddu; the old woman says he is away buying wine. Alfio arrives with his friends, boasting of his horses—and of his new wife, Lola (“Il cavallo scalpita”). He leaves as the villagers follow a procession to mass. Santuzza, who is unwilling to enter the church, stays behind to tell Mamma Lucia that Turiddu has abandoned her for his old flame, Lola (“Voi lo sapete”). The old woman leaves for mass, and Santuzza confronts Turiddu (“Tu qui, Santuzza?”). Lola saunters in, infuriating Santuzza with her brazen arrogance. Lola enters the church, and Santuzza resumes her pleading, but Turiddu refuses to listen. Pushing her to the ground, he runs into the church. Santuzza curses him. When Alfio arrives, Santuzza reveals that his wife has been cheating on him. Alfio swears to get even and rushes off, followed by the now conscience-stricken Santuzza.
The villagers exit the church and join Turiddu in a drinking song, but the atmosphere becomes tense when Alfio appears, insulting Turiddu and challenging him to a knife fight. Turiddu admits his guilt but will go through with the fight, for Santuzza’s sake as well as for honor. Alone with his mother, Turiddu thanks her for the wine and begs her to take care of Santuzza if he doesn’t come back (“Mamma, quel vino”). As Mamma Lucia waits anxiously in the piazza, shouts are heard in the distance. A woman runs in screaming that Turiddu has been killed.
Before the opera begins, Tonio the clown steps before the curtain (“Si può?”) to announce that the author has written a true story and that even actors and clowns have the same joys and sorrows as other people.
Villagers in a town in Calabria gather around a small theatrical company that has just arrived. Canio, the head of the troupe, describes the night’s offerings (“Un grande spettacolo”). When one of the villagers suggests that Tonio is secretly courting Canio’s wife, Nedda, Canio warns that he will tolerate no flirting off stage (“Un tal gioco”). Vesper bells call the women to church and the men to the tavern, leaving Nedda alone. Disturbed by her husband’s jealousy, she envies the freedom of the birds in flight (“Stridono lassù”). Tonio tries to force himself on her. She beats him back and he swears revenge. In fact, Nedda does have a lover—Silvio, who appears and persuades her to run away with him after the evening’s performance (“E allor perchè”). Tonio overhears this and hurries off to tell Canio. The jealous husband bursts in on the guilty pair, but Silvio runs away before Canio can identify him. Nedda, even when threatened with a knife, refuses to reveal the man’s name. Beppe, another clown, restrains Canio and Tonio advises him to wait until the evening’s performance to catch Nedda’s lover. Alone, Canio bitterly reflects that he must play the clown while his heart is breaking (“Vesti la giubba”).
The villagers, including Silvio, assemble to see the commedia dell’arte performance.
Harlequin (played by Beppe) serenades Columbine (Nedda) and dismisses her buffoonish servant Taddeo (Tonio). The two lovers dine together and plot to poison Columbine’s husband Pagliaccio (played by Canio), who soon arrives. Harlequin slips away. With pointed malice, Taddeo assures Pagliaccio of his wife’s innocence, which ignites Canio’s jealousy. Forgetting the play, he demands Nedda tell him the name of her lover (“No, Pagliaccio non son”). She tries to continue with the play, the audience enthralled by its realism. Enraged, Canio stabs Nedda and Silvio, who rushes to help her. Tonio announces to the horrified villagers that the comedy is ended.