Housekeeper Florence Pike is run ragged. Her mistress Lady Billows is organizing the annual May Day festival, and has gathered all the important people of the village to vet nominees for the coveted position of Queen of the May. But Florence has dug up dirt on every single girl nominated, proving that none is worthy to wear the May Queen's crown. Lady Billows is depressed. Superintendent Budd suggests that the solution may be to select, this year, a May King instead of a May Queen. He knows of a young man in town who is as certainly virginal as the girls are not: Albert Herring.
At the greengrocer's, Albert is teased for his timidity by the easygoing Sid. Sid's girlfriend Nancy comes in to do some shopping, and the couple shares a tender moment while Albert eats his heart out. The lovers leave, and Albert reflects on his miserable existence under his mother's thumb. The Festival Committee arrives with the news of his selection as May King. Mrs. Herring is thrilled, Albert less so. Mother and son quarrel, to the mocking commentary of the village children.
It is the day of the festival. Sid and Nancy are preparing the banquet tent, and they take the chance to slip some rum into Albert's lemonade glass. Albert is tongue-tied at the feast in his honor, but drinks his lemonade greedily, which Britten satirically illustrates with a quote from Richard Wagner's Tristan und Isolde. Together with his crown of flowers and the gruesome but improving Foxe's The Book of Martyrs, he is awarded twenty-five pounds in prize money.
That night, Albert arrives home alone, quite drunk. In the street, Sid keeps a date with Nancy, and the two discuss their sympathetic pity for Albert before going off together. This is finally the breaking point for Albert. He takes the prize money and heads out looking for adventure.
The next morning Albert has not returned, and the village is in a panic. Superintendent Budd is leading a search, while the guilt-stricken Nancy tends to Mrs. Herring. A boy shouts that a "Big White Something" has been found in a well, and the village worthies file in to break the news en masse that Albert's crown of flowers has been discovered, crushed by a cart. Clearly, he is dead. A lengthy threnody of grief is interrupted by the surprise return of Albert. He thanks the Festival Committee for providing him with the cash for his night out. They, in turn, are outraged by his tale of drunken debauchery, and leave in a huff. Albert finally stands up to his mother, and invites the village kids into the shop to sample some complimentary fruit.