As Figaro and Suzanne are about to kiss, the Countess enters and tells Figaro that the Count is waiting for him to begin the ceremony.

Alone with Suzanne, the Countess shares that she is ready to meet the Count in the garden. She will disguise herself as Suzanne and meet the Count, who expects to have an affair with Suzanne. The Countess suggests that Suzanne should write to the Count and arrange a time for their meeting. They write the note together, writing a “new lyric to the old tune” (175). The letter tells the Count to meet in the garden beneath the chestnut trees. They seal the letter with a pin from the Countess’s clothes, then they will ask the Count to return the pin in lieu of a reply. 

As they are sealing the letter, Cherubin’s ribbon slips out of the Countess’s dress. Suzanne is shocked to see the blood-stained ribbon, but the Countess suggests that she will give it to Fanchette rather than keep it for herself.

Just as the Countess and Suzanne note the fallen ribbon, Fanchette enters with other female servants. Among them is Cherubin, now disguised as a female shepherd. The Countess subtly slips the ribbon into her clothing. She greets the disguised Cherubin with a kiss as Fanchette introduces the shepherd as her cousin. Though the Countess suspects that the disguised shepherd is actually Cherubin, they are interrupted by the arrival of the Count, who is accompanied by Antonio.

Antonio suspects that one of the female servants is Cherubin in disguise, since he found clothing hidden in a basket. The servants surround the shepherd, seeking to protect Cherubin from scrutiny, but Antonio removes the disguise and places a military cap on Cherubin’s head instead. The Countess claims to be “even more surprised than [the Count] and at least as angry” (177). She blames the Count for ruining the earlier prank, as all the confusion has stemmed from this “general panic.” 

Fanchette steps forward, revealing that the Count has tried to seduce her on multiple occasions. During their affair, the Count promised to give her anything that she desired. Now, Fanchette asks whether the Count will allow her to marry Cherubin. The Countess takes Fanchette’s claims as proof of her innocence and proof of her husband’s infidelities. The Count feels as though “some evil genius” is plotting against him (178).

Figaro enters, telling everyone that the wedding is about to begin. He is eager to dance; the Count disputes this, believing that Figaro injured his ankle when he jumped from the window. The Count also tells Figaro that Cherubin defied him and is now disguised among the female servants. The Count reveals that he knows the truth: Cherubin, not Figaro, leapt from the window and broke the flowerpot. Though Figaro insists that he and Cherubin jumped from the window together, the Count is angry that they have strayed into “some kind of farce” (179).

As a fanfare calls the guests to the wedding, Cherubin is left with the Count and Countess. The Count angrily orders Cherubin to dress himself properly and to stay out of the Count’s sight for the rest of the evening. The Countess complains that the page will be “so bored,” but the Count is too angry to care.

Cherubin departs, and the Countess fans herself vigorously. Noting something strange on his head, the Countess dismisses the Count’s comment by claiming that it must be his military cap, since “boys love toys” (180). The Countess claims that she is not feeling well. The Count agrees that they must endure the wedding for the sake of politeness.

The wedding ceremony begins. There will actually be two weddings, first between Marceline and Bartholo, then between Figaro and Suzanne. As the procession gets underway, Suzanne hands a note to the Count. Amid the dancing, the Count tries to read the note. He pricks his finger on the pin, which he throws on the ground, and curses women who “stick pins in everything” (181). When he returns to the note, he is pleased by the contents, believing that Suzanne intends to meet him in the garden. 

Figaro notices the Count reading a note and presumes that a woman has written to him to arrange the meeting. The Count recovers the dropped pin, having read that he must return it, but Figaro believes this is an example of the Count trying to keep a token of a woman’s love. Suzanne and the Countess watch the Count read the letter. They believe that he has fallen for their plot. They exit the ceremonies to swap clothes as Bazile arrives with the whole village as his entourage, intending to stop the wedding.

Bazile enters with Grippe-Soleil beside him. Bazile plays his guitar and sings a song about love. Figaro asks the reason for this intrusion, and Bazile responds that he seeks the Count’s justice. He wants to marry Marceline. Figaro insults Bazile; the two men nearly fight, but they are held apart by Don Gusman and Bartholo. 

The Count orders that the “impudent ruffians” must stop their dispute. Bazile reveals that Marceline had promised to marry him on the condition that he adopt her long-lost son. Bazile learns that, in fact, Figaro is Marceline’s long-lost son. This revelation dissuades him from his plans. He has no interest in adopting Figaro, thus he does not want to marry Marceline any longer. Bazile exits.

Figaro and Bartholo celebrate Bazile’s departure as the Count offers to sign the marriage contracts. As the crowd cheers him, the Count seeks “an hour to [himself]” (185). The crowd exits.

Grippe-Soleil claims that he must help organize the firework display being set up under the chestnut trees. Overhearing this, realizing that this is where he is supposed to rendezvous with Suzanne, the Count returns. He asserts that, since the Countess is unwell, she will be unable to see the fireworks from this position, so the fireworks will be moved to the terrace.

Figaro is left alone with Marceline. He speaks to her about how he never suffers from jealousy, which he claims is the “foolish offspring of pride” (186).

Fanchette enters. She has the pin used to seal the Countess’s letter. The Count sent her, she explains to Figaro, to return the pin to Suzanne with the message that they should meet beneath the chestnut trees and that Fanchette should tell no one about her errand. Figaro sends Fanchette away.

Recognizing the pin as the love token he saw in the Count’s hands, Figaro is suddenly afraid that Suzanne actually plans to have an affair with the Count. He does not know about her plot with the Countess. He launches a plot of his own to confound the Count and Suzanne’s apparent affair. Marceline is not so sure that Suanne is having an affair, but she cannot convince Figaro, as he is overcome with jealousy.

Left alone, Marceline hopes that she has satiated her son’s jealousy and plans to warn Suzanne. Women, she believes, should stick together and defend themselves against the “rather simple-minded male sex” (189).