John "Jack" Worthing's background provides the play with its mystery and plot conflicts, which start and end with his name. Jack leads a double life. He goes by the name of Ernest when he's in town and by Jack when he's in the country. Although he thinks he has invented Ernest, at the end of the play he learns that Ernest is really his name. Jack's character reveals certain contradictions. Jack is, by his own account, habitually dishonest. He even apologizes for telling the truth. On the other hand—although his deception has allowed him the freedom to indulge in the behavior Jack disapproves of—as the play opens he is in London not to misbehave but to court Gwendolen, whom he loves and wants to marry. Also he takes his country responsibilities seriously, including his guardianship of Cecily. If his double life has been hypocritical, by the start of the play Jack seems ready to confront the situation and go beyond it.
Algernon is an idler and a dandy, a young, upper-class man who lives for pleasure, does not work, and moves from one social venue to another. If there is a challenge in his life, it is in aligning his pleasures just as he wants them and in not irritating his relatives too much. He also is bright and inventive, having created an invalid friend named Bunbury, whom he uses as an excuse to avoid unpleasant or unwanted social obligations. Algernon mocks social conventions but ends up living one of the most clichéd conventions in fiction: falling in love at first sight with Cecily Cardew. Algernon's actions drive the plot. It is "Algy" who listens in on Jack telling Gwendolen where he lives and shows up there; it is Algy who pretends to be Ernest so he can meet and woo Jack's ward, Cecily. Algernon is the play's engine.
A shallow and conventional young woman, a well-indoctrinated product of conventional upper-class Victorian society, Gwendolen seems sure of herself and sure of what she wants in life. Some of these desires, however, seem like mockery. She wants love but is obsessed with the idea of marrying someone named Ernest. Even with her rational explanation, she sees the qualities of earnestness in a name rather than in a person. She appears smart and sophisticated, but only superficially. Gwendolen demonstrates her superficiality in her behavior toward Cecily as well. She is quite affectionate toward Cecily at first but quickly becomes her enemy when it appears they are engaged to the same man. Similarly when Jack's deception over his name is revealed, she is momentarily angry with him.
Cecily is the granddaughter of Thomas Cardew, who adopted Jack. She is quite sheltered, having spent her life in the country rather than in the city, and is chafing under Jack's rules and Miss Prism's tutelage. Of all the characters, naive and innocent Cecily shows the loosest relationship to reality. This gap between fantasy and fact is clearly demonstrated when finally she meets Algernon (playing the part of Ernest). When Algernon says he loves her and wants to marry her, Cecily reveals that they've already been engaged for three months—a fantasy she has created, having fallen for the wayward Ernest solely on the basis of Jack's accounts. It is notable that the sophisticated Gwendolen and the naive Cecily both are taken with the idea of "Ernest"—Gwendolen for the admirable qualities of the word and Cecily for the negative qualities of the character.
Lady Bracknell is the voice of authority and speaks with all the haughty self-righteousness of the conventional Victorian upper-class matron. An expert at social interaction, she is brash, interfering, greedy, and snobbishly conservative. She expects to be served and obeyed, and she is. One of her primary interests is to secure a suitable—in her world, rich and well-connected—husband for her daughter.