The play begins at the English countryside estate of Lady Huntstanton. One of the guests, Lady Caroline Pontrefact, is discussing the other guests with Hester Worsley, a young American woman who is an orphan with a vast fortune. Lady Caroline is judgmental and snobbish, disapproving of Hester’s fondness for a young man named Gerald Arbuthnot who, to Lady Caroline’s consternation, has a job and works in a bank. The two remark on how Gerald has just been offered the position of secretary to the wealthy and popular aristocrat Lord Illingworth, which will help Gerald establish a promising career. To celebrate this news, Lady Hunstanton decides to invite Gerald’s mother, Mrs. Arbuthnot, to dinner later that night. Lady Hunstanton hopes this piece of good news will persuade Mrs. Arbuthnot to join them, even though Mrs. Arbuthnot typically avoids society gatherings.

The guests gossip and engage in a discussion about the role of women in society. A politician named Mr. Kelvil asserts that women are more morally pure than men and therefore help to influence society for the better. Then, Lord Illingworth enters the room. He has a reputation for being flirtatious and immoral, though he is still charming.