Act I

The Count of Almaviva is in love with the beautiful Rosina, who lives in the house of her elderly guardian, Don Bartolo, who in turn secretly intends to marry her. The Count asks Figaro, a barber and "city factotum," to help him win the girl's heart, to whom he introduced himself under the false name of Lindoro.Figaro advises the Count to change his personality and pretend to be a young drunken soldier. Rosina soon shows interest in him, thanks also to a beautiful serenade sung beneath her uncle's house windows; the barber also provides Lindoro with a document attesting to his temporary residence in Don Bartolo's house and tries to establish a relationship with Rosina.Don Basilio, the girl's music teacher, knows of Count Almaviva's presence in Seville and suggests to Don Bartolo that he slander him to diminish his reputation. He arrives at the house, surprising Figaro and Rosina. However, the girl had already written a note for Lindoro, but Don Bartolo notices a page missing from her notebook and scolds Rosina.According to the plan, Count Almaviva bursts into Don Bartolo's house pretending to be a drunken soldier, but creates such confusion that the gendarmes arrive. However, when the Count secretly reveals his identity to the officer, the soldiers stand at attention, leaving Don Bartolo astounded.

Act II

Don Bartolo begins to suspect the true identity of the young soldier Lindoro. The self-proclaimed music teacher Don Alonso arrives (in reality, still the Count, hidden under a new disguise), claiming to have been sent by Don Basilio, who remained home with a fever, to replace him for Rosina's singing lesson.To gain the guardian's trust, the fake Don Alonso shows him the note Rosina had sent him. Meanwhile, Figaro arrives with the task of shaving the landlord. Despite Figaro doing his best to cover the young couple's conversation, Don Bartolo overhears their words and chases everyone away. Only Berta, the servant, remains with him, commiserating with the old master.Don Bartolo makes Rosina believe, by showing her the note handed to him by Don Alonso, that Lindoro and Figaro want to make a fool of her, and the embittered girl agrees to marry her guardian, who promptly calls the notary. At that moment, Don Basilio also arrives, while Figaro and the Count enter the house through the window with a ladder and reach Rosina. Finally, the Count reveals his true identity to clarify the situation and convince the maiden of the sincerity of his love.However, Don Bartolo had the ladder removed, and the three accomplices find themselves without a way out. At that moment, the notary called to draw up the marriage contract between Don Bartolo and Rosina arrives. Taking advantage of the guardian's temporary absence, the Count asks Figaro and Don Basilio (for a suitable reward) to act as witnesses and insert his name into the contract in place of Don Bartolo's. Arriving too late, Don Bartolo is left with the meager consolation of having saved Rosina's dowry, which Count Almaviva refuses. The lovers thus fulfill their dream.