Set in the days before the land rush in what is now the state of Oklahoma, the story begins on a radiant morning. A local ranch hand named Curly wanders by (Oh, What a Beautiful Mornin’) and greets the cheery Aunt Eller. Curly really wants to invite Laurey, Aunt Eller’s niece, to the box social that night. Laurey and Curly spar with each other good-naturedly, with her spurning him because he can’t take her out in the style to which she wants to be accustomed (The Surrey with the Fringe on Top).

In the meantime, Will Parker, a wild young neighbor, has returned with stories of the big city (Kansas City). Will’s erstwhile fiancée, Ado Annie Carnes, has become involved with a traveling salesman (I Cain’t Say No). Laurey has angered Curly by accepting a date to the box social with Jud Fry, the sinister hired hand. When Curly is still playing games with her, Laurey tells her friends how little she cares (Many a New Day). Laurey and Curly talk again, though, and Laurey is coy about what people will think (People Will Say We’re in Love). She’s still giving Curly a hard time, so Curly goes down to the smokehouse where Jud lives to see what the fuss is all about.

The tormented Jud does not welcome Curly, and he is even more upset by Curly’s suggestion – that if he hanged himself, it would be the first popular thing he ever did (Pore Jud is Daid). As they prepare to leave for the party, Laurey is suddenly uncertain and wants more time to understand what Curly means to her (Out of my Dreams).

At the party, Judge Andrew Carnes, Ado Annie’s father, tries to bridge the antipathy between the two warring groups of settlers (The Farmer and the Cowmen). The partygoers begin to bid on hampers of home-cooked food, and a duel of bids ensues between Jud and Curly for Laurey’s hamper. Curly wins. Ado Annie and Will Parker finally set a date, though there have to be a few new rules for the bride-to-be (All Er Nothin’). Jud dances off with Laurey and forces himself on her. Disgusted she fires him and breaks down when Curly finds her. They admit their love for each other.

Three weeks later, they are married. Jud reappears and, when he tries to kiss Laurey, Curly attacks him. In the fight between them, Jud falls on his knife and is killed. Although the sheriff Cord Elam wants to jail Curly, Judge Carnes holds court then and there and pronounces Curly not guilty. A celebration of a brand new life breaks out (Oklahoma), and the lovers take off on their honeymoon.