After losing the Iowa presidential caucuses, Senator John Falstaff stirs up trouble in Windsor, Iowa. At the play's opening, while townsfolk are preparing for the State Fair, he's accused of campaign finance misdeeds against Mayor Roberta Shallow and her niece, Slender. Farmer George Page and Reverend Hugh Evans, a Canadian come to Iowa to help the state's transition to legalized gay marriage, work to make peace. Roberta suggests that perhaps Slender could refill the family coffers by marrying George's daughter, Anne. Hugh enlists Miss Quickly's help to keep away another suitor: her employer, Doctor Kaya. Kaya, enraged by Hugh's intervention and an unresolved sports competition, challenges him to a duel.
Since he and his campaign are broke, Falstaff's remaining staff members, Pistol and Nym, take jobs at the Come On Inn, where the manager is preparing to enter her beloved boar for a prize at the Iowa State Fair. Falstaff decides to woo a married woman, hoping to gain access to her spouse's bank account. Then, to improve his odds, he woos two: The first, Alice Ford, is married to a woman; the second, Margaret Page, to a man. When Pistol and Nym reveal his designs to the women's spouses, the jealous Francie Ford visits Falstaff disguised as man, hoping to find out whether her wife is faithful. The targeted wives team up to play Falstaff for a fool. Francie fails to catch Falstaff in the "affair," since the clever wives help him escape her outraged searches.
Meanwhile, a contest ensues for the hand of Anne Page. Her mother, Margaret, favors Kaya. Her father, George, wants her to marry Slender. Anne herself loves a young man named Fenton. A duel between Doctor Kaya and Abby's champion, Reverend Hugh, is interrupted by the inn's manager, who sends them to different locations for the fight. In revenge, Dr. Kaya and Reverend Hugh pretend to be FBI agents and foil the manager's plan to enter her boar at the Fair.
Once Francie and George learn the details of their wives' responses to Falstaff's wooing, all collaborate on Falstaff's final comeuppance. They plan to lure him to the Fair with promises of public honor (which they will turn into public humiliation). In the midst of it all, Anne's parents plan for her elopements with Kaya and Slender in disguise, while Anne makes plans of her own.