After a shipwreck separates twins Viola and Sebastian, Viola disguises herself as a man to navigate the unfamiliar territory of Illyria, triggering a complex web of romantic confusion. Viola enters the service of Duke Orsino, who is infatuated with the Countess Olivia, while simultaneously becoming the object of Olivia's affection. The narrative operates through a series of dramatic ironies, where characters act upon false information regarding the identities and intentions of those around them. The play utilizes a traditional five-act structure to balance the high-stakes romantic entanglements with the low-stakes, satirical subplot involving the household of Olivia.

Discussion often centers on the intricate balance between the play's comedic farce and its underlying currents of loneliness and unrequited longing. Readers frequently highlight the character of Malvolio as a focal point for debates regarding the cruelty of the play's humor and the nature of social ambition. Critics often examine how the text utilizes the setting of Illyria to create a liminal space where traditional social hierarchies are temporarily suspended. The play's conclusion is frequently analyzed for its refusal to provide a purely celebratory ending, noting how the clown's final song introduces a somber reflection on the passage of time. Many observers note that the work remains a primary example of how Shakespeare uses language to explore the subjective and often irrational nature of human affection.