Sir John Falstaff, a knight down on both luck and cash, hatches a scheme to raise funds. He will seduce Mistress Ford and Mistress Page in an attempt to get at their husbands' money. Falstaff, however, has overestimated his ingenuity; the two women compare their letters and— finding them identical—hatch a plan of their own to make a buffoon of the knight. They encourage his advances. In the meantime, Pistol and Nym, whom Falstaff has sacked, go to Ford and Page's husbands with the news. Ford, who is jealous and paranoid, disguises himself and meets Falstaff. He pretends to be an illicit lover who wishes to hire Falstaff to woo Mistress Ford on his behalf, to which Falstaff agrees.

As Mistresses Ford and Page pursue their sport, Falstaff is first hidden in a basket of dirty laundry and cast into the Thames, then later dressed as a woman and beaten. Finally, the women tell their husbands about their secret revenge, and all plot one last humiliation for the feckless Falstaff. As this is going on, Page's daughter, Anne, is being courted by three suitors, only one of which she actually cares for: Fenton. Anne is included in the plans for Falstaff; she is to lead the children of the town—all dressed as fairies—in an attack on the knight as he waits in the woods for Mistress Ford and Mistress Page. As they prepare for the final prank, the husband Page pulls Slender (one of Anne's suitors) aside and tells him to elope with her that evening; Mistress Page pulls her favourite suitor, Doctor Caius, aside and says she wants him to elope with Anne. The two men are to recognize Anne (she'll be wearing a mask, after all) by the colour of dress she wears. To add to this, Anne makes plans of her own to elope with her beloved Fenton.

Falstaff, dressed as Herne (complete with antlers), is mercilessly tormented by the children dressed as fairies. The wives and husbands eventually reveal themselves to the much chagrined Falstaff, who is forgiven by all. In the midst of this resolution, Slender and Doctor Caius reappear. It seems that Slender thought Anne was to wear a white dress; Caius believed her to be wearing green. Both men, having erred on the colour of her dress, mistakenly ran off with boys instead of Anne. Fenton arrives with Anne in their wake; the two have married, and Anne's parents begrudgingly accept the fact.