Gwendolen is Algernon's cousin. She is also Lady Bracknell's daughter. She is not only elegant and fashionable, but also artificial and pretentious. She is in love with Jack because she finds him irresistible solely because of her belief that Jack's name is Ernest. She swears that she cannot marry any man who is not called Ernest. This obsession of Gwendolen's sustains the plot, as it stands in sharp contrast to Lady Bracknell's adherence to social convention. By what society approves, an eligible suitor cannot but be on her list, even if he is not Ernest. In contrast, Gwendolen's man need only be Ernest whether he is a man of enough substance to earn a place on her mother's list.
Gwendolen exposes the misplaced notion of the society about the nature of men. A man is seen as all strength, manliness and capability. Contrary to this, at the crucial moment, Jack stammers while Gwendolen takes over and steers the process of the marriage proposal herself. As part of the hypocritical system, she pretends, on her meeting Cecily that she does not mind being in the company of a girl of the countryside. The argument between her and Cecily when the two become entangled in the confusion of which Ernest each is in love with reveals their infatuation with symbols appearances rather than reality. Thus, it is Gwendolen's resolve to marry only a man named Ernest that moves the plot forward. Her position leads Jack to his desire to be christened. This in turn leads to revelation that Jack, after all, is Ernest. He actually has been christened as such.