When the novel opens, the artist is completing his first portrait of Dorian as he truly is, but, as he admits to his friend Lord Henry Wotton, the painting disappoints him because it reveals too much of his feeling for his subject. Lord Henry, a famous wit who enjoys scandalizing his friends by celebrating youth, beauty, and the selfish pursuit of pleasure, disagrees, claiming that the portrait is Basil´s masterpiece. Dorian arrives at the studio, and Basil reluctantly introduces him to Lord Henry, who he fears will have a damaging influence on the impressionable, young Dorian.

Basil´s fears are well founded; before the end of their first conversation, Lord Henry upsets Dorian with a speech about the transient nature of beauty and youth. Worried that these, his most impressive characteristics, are fading day by day, Dorian curses his portrait, which he believes will one day remind him of the beauty he will have lost. In a fit of distress, he pledges his soul if only the painting could bear the burden of age and infamy, allowing him to stay forever young. In an attempt to appease Dorian, Basil gives him the portrait.

Over the next few weeks, Lord Henry´s influence over Dorian grows stronger. The youth becomes a disciple of the “new Hedonism” and proposes to live a life dedicated to the pursuit of pleasure. He falls in love with Sibyl Vane, a young actress who performs in a theater in London´s slums. He adores her acting; she, in turn, refers to him as “Prince Charming” and refuses to heed the warnings of her brother, James Vane, that Dorian is no good for her. Overcome by her emotions for Dorian, Sibyl decides that she can no longer act, wondering how she can pretend to love on the stage now that she has experienced the real thing. Dorian, who loves Sibyl because of her ability to act and thinks that without art she is nothing, cruelly breaks his engagement with her. After doing so, he returns home to notice that his face in Basil´s portrait of him has changed: it now sneers. Frightened that his wish for his likeness in the painting to bear the ill effects of his behaviour has come true and that his sins will be recorded on the canvas, he resolves to make amends with Sibyl the next day. The following afternoon, however, Lord Henry brings news that Sibyl has commited suicide. At Lord Henry´s urging, Dorian decides to consider her death a sort of artistic triumph – she personified tragedy – and to put the matter behind him.