The Importance of being Earnest is a farcical romp in which the protagonists don fake personas to shirk the burdens of their social obligations. They are Algernon Moncrieff and Ernest Worthing, young gentlemen leading double lives. Algernon inquires why the cigarette case belonging to "Ernest" bears the name "Jack." Earnest confesses that while in the country taking care of his young ward Cecily, he's Jack; here he claims to be taking care of his profligate brother Earnest in London. When he's in London, however, he becomes the rakish Earnest. Algernon admits to the same ruse: while in country, he tells his London friends he's visiting an invalid friend named "Bunbury."

Wilde's hilarious and biting play pokes fun at the social order of Victorian England, while showcasing the author's classic witty epigrams (short, often paradoxical sayings) for which he is famous.