Dorian Gray is the subject of a full-length portrait in oil by Basil Hallward, an artist who is impressed and infatuated by Dorian's beauty; he believes that Dorian's beauty is responsible for the new mode in his art as a painter. Through Basil, Dorian meets Lord Henry Wotton, and he soon is enthralled by the aristocrat's hedonistic worldview: that beauty and sensual fulfilment are the only things worth pursuing in life.

Newly understanding that his beauty will fade, Dorian Gray expresses the desire to sell his soul, to ensure that the picture, rather than he, will age and fade. The wish is granted, and Dorian pursues a libertine life of varied and amoral experiences, while staying young and beautiful; all the while his portrait ages and records every sin.

The plot of the novel varies between each of the published versions. The summary below deals with the longest version, the 1891 novel. However, certain episodes described-in particular Dorian's encounter with, and murder of, James Vane-do not appear in the version originally submitted by Wilde to Lippincott's.

The Picture of Dorian Gray begins on a beautiful summer day in Victorian era England, where Lord Henry Wotton, an opinionated man, is observing the sensitive artist Basil Hallward painting the portrait of Dorian Gray, a handsome young man who is Basil's ultimate muse. While sitting for the painting, Dorian listens to Lord Henry espousing his hedonistic world view, and begins to think that beauty is the only aspect of life worth pursuing. This prompts Dorian Gray to wish that the painted image of himself would age instead of himself.

Under the hedonistic influence of Lord Henry, Dorian fully explores his sensuality. He discovers the actress Sibyl Vane, who performs Shakespeare plays in a dingy, working-class theatre. Dorian approaches and courts her, and soon proposes marriage. The enamoured Sibyl calls him "Prince Charming", and swoons with the happiness of being loved, but her protective brother, James, warns that if "Prince Charming" harms her, he will murder him.