As the story opens, young college graduate Eric Marshall agrees to substitute teach in the village of Lindsey for a friend who has taken ill. On an evening ramble, he discovers a neglected orchard, and a beautiful woman who plays the violin in a bewitching manner.

The innocent young woman, whose name is Kilmeny, has a tragic history and a stunning diability; she is unable to speak. She communicates with Eric by writing on a slate. The two become close friends. Eric is reminded of his obligations as a man by his friendly landlady Mrs. Williamson, and he elects to declare his intentions to Kilmeny's guardians, the Gordons.

Eric will face several obstacles to his love for Kilmeny: Kilmeny's protective relatives; Kilmeny herself, who believes she is unworthy of marriage; Neil Gordon, a deadly rival for Kilmeny's affections; and Eric's own skeptical father. Eric will have to prove himself worthy of Kilmeny in an exciting conclusion.

According to Montgomery biographer Elizabeth Waterston, "Kilmeny of the Orchard" is a longer version of a short story written in 1908. The novel was the third written by Montgomery following "Anne of Green Gables" and "Anne of Avonlea." It is highly recommended to fans of L.M. Montgomery as a short but entertaining example of her imaginative writing.