While preparing for their wedding, the valet Figaro learns from the maid Susanna that their philandering master, Count Almaviva, has his eye on her. At this, the servant vows to outwit his master. Before long Dr. Bartolo enters with the palace housekeeper, Marcellina, who wants Figaro to marry her to cancel a loan he cannot repay. Marcellina and Susanna trade insults until the amorous page Cherubino arrives, reveling in his infatuation with all women. The Count enters, furious at having caught Cherubino flirting with the gardener’s daughter Barbarina, and the page hides not a moment too soon. The Count pursues Susanna and conceals himself when the gossiping music master Don Basilio approaches, only to reemerge when Basilio mentions Cherubino’s infatuation with the Countess. The Count becomes livid when he finally discovers Cherubino hiding in the room. Figaro returns with fellow servants praising the Count’s progressive reform in abolishing the droit du seigneur—the right of a noble to take a manservant’s place on his wedding night. The Count banishes Cherubino to serve in his regiment and leaves Figaro to cheer up the distraught adolescent.
The Countess laments her husband’s waning love but plots to chasten him, with help from Figaro and Susanna. They will send Cherubino, disguised as Susanna, to a romantic tryst with the Count. Cherubino, smitten with the Countess, appears and the two women begin to dress the page for his rendezvous. While Susanna goes out to find a ribbon, the Count knocks on the door, furious to find it locked. Cherubino quickly locks himself in the closet, and the Countess admits her husband. The Count soon hears a noise coming from the closet and doubts the Countess’s claim that Susanna is inside the closet. He takes his wife to fetch some tools with which to force open the closet door. Meanwhile, Susanna, having observed everything from behind a screen, urges Cherubino to come out. Cherubino leaps from the window to escape, and Susanna takes his place in the closet. Both the Count and the Countess are amazed to find her there upon their return. All seems well until the gardener, Antonio, storms in with crushed geraniums from a flower bed below the window. Figaro, who has run in to announce that the wedding is ready, contends it was he who jumped from the window and feigns a sprained ankle. Marcellina, Bartolo, and Basilio burst into the room waving a court summons for Figaro, which delights the Count since this gives him an excuse to delay the wedding.