Scene 1: Leporello bemoans his destiny as a servant to Don Giovanni ("Notte e giorno faticar" – "Night and day I slave away"). His master and Donna Anna emerge from the palace struggling, as Anna tries to identify the disguised person who attempted to seduce her in her bedroom (Trio: "Non sperar, se non m'uccidi, Ch’io ti lasci fuggir mai!" – "Do not hope, unless you kill me, that I shall ever let you run away!"). Her father, Commandant of Seville, alarmed by his daughter’s cries, challenges the attacker. Don Giovanni kills the old nobleman. Donna Anna returns with her fiancé, Don Ottavio, but they are too late to save her father.
Scene 2: Donna Elvira, abandoned lover and would-be wife, arrives by train in search of the Don. Don Giovanni, who is on an amorous adventure at the train station, unwittingly approaches Elvira. He escapes, leaving Leporello to show Elvira to the Don’s “not-so-little black book” of conquests. ("Madamina, il catalogo è questo" – "My dear lady, this is the catalogue")
A group of peasants arrive in a park for a pre-wedding celebration for Zerlina and Masetto. Giovanni immediately tries to charm the young bride, much to the chagrin of her fiancé, who dares to stand up for his rights ("Ho capito! Signor, sì" – "I understand! Yes, my lord!"). In vain, he is taken off by Leporello, leaving the Don to attempt further seduction (Duet: "Là ci darem la mano" – "There we will entwine our hands"). Elvira enters and warns the girl against the intentions of the traitor ("Ah, fuggi il traditor" – "Flee from the traitor!"). As the women leave, Anna and Ottavio arrive to ask Giovanni for help in finding her father’s assassin. Elvira interrupts and begs the two nobles not to trust Giovanni, who in turn, indicates that Elvira has lost her mind (Quartet: "Non ti fidar, o misera" – "Don't trust him, oh sad one"). He then takes leave of the two, and Anna suddenly realizes that Giovanni is the man who attacked her. (Anna aria: "Or sai chi l'onore Rapire a me volse" – "Now you know who is the one having trying to rob me of my honour"). She asks Ottavio to avenge her father.
Scene 3: Before the party that he promised the peasants, we find Don Giovanni singing of his happy pursuit of love ("Champagne Aria": "Fin ch'han dal vino calda la testa" – "Till they are tipsy"). Zerlina begs Masetto’s forgiveness for her behavior and assures him that she did not fall for the advances of the Don ("Batti, batti o bel Masetto" – "Beat o beat me, handsome Masetto"). However, when the Don appears, the jealousies of the bridegroom flare up again. Dance music is heard in the distance and Anna, Elvira, and Ottavio, who are masked, are invited to the party. They swear to punish the libertine (Trio: "Proteggra il giusto cielo" – "May the just heavens protect us").
Scene 4: At the party, Giovanni takes advantage of the busy crowd to lead Zerlina into his private quarters. When she calls out for help, the three masked guests reveal their identities to the Don and Don Ottavio threatens Giovanni with a pistol. Giovanni escapes the wrath of his guests.
Scene 1: As Don Giovanni wants to attract the attention of Elvira’s maid, he exchanges cloaks and hats with Leporello and sings first to Elvira, while his servant is miming the words. As Elvira leaves with the disguised Leporello, Giovanni serenades the servant girl ("Deh vieni alla finestra" – "Ah, come to the window"). Masetto and a band of angry peasants, who are after the Don, are sent by Giovanni (in his Leporello disguise) in the wrong direction. He assalts Masetto. Zerlina consoles her groom with tender care "Vedrai carino" – "You'll see, dear one”). Elvira is still furious at Giovanni for betraying her, but she also feels sorry for him. ("Mi tradì quell'alma ingrata" – "That ungrateful wretch betrayed me").
Scene 2: Leporello, still in disguise, tries to flee from Elvira, but instead is met by Anna, Ottavio, Zerlina and Masetto, who all want their revenge. The servant finally unmasks, begs for forgiveness and flees the scene.
Scene 3: Don Giovanni and Leporello exchange their recent experiences and thereby mock the deceived women. As they are leaving the graveyard, they hear a voice and recognize the tomb of the slain Commandant. Don Giovanni insists that Leporello read the inscription on the tomb. “I wait to avenge my wrongful death.” Giovanni forces the petrified servant to invite the statue to dinner. Shaken, the two perceive a positive response to the invitation.
Scene 4: In her home, Anna, still in mourning, puts off Ottavio's offer of marriage until her father is avenged ("Non mi dir" – "Tell me not").
Scene 5: Don Giovanni is still leading a life of debauchery, interrupted only briefly by Elvira, who makes a final, desperate attempt to save the Don ("L'ultima prova dell'amor mio" – "The final proof of my love"). The Don becomes a victim of the demons of guilt that he has, until now, fended off through a dissolute life. In his alcoholic stupor, he perceives the avenging voice of the Commandant and is carried off to his own Hell.