George Sedley Osborne, John Sedley's godson, has been close to the Sedley family all his life. He and Joseph have gone to school together. Old Osborne has commanded him to marry Amelia, and this plan has been understood for years.
George Osborne belongs to Vanity Fair. As a boy he has been ashamed of William Dobbin, his protector at school, because he feels Dobbin is of a lower social status. His sisters convince him he is one of the most deserving characters in the British Army, and "he gave himself up to be loved with a great deal of easy resignation."
George loves Amelia after his fashion, but he loves himself more; and often when his sisters think he is with Amelia, he is gambling, drinking or going to the theater. Popular with the men in the regiment because of his outstanding sportsmanship, he equally charms the ladies:
His whiskers had made an impression upon her . . . George had an air at once swaggering and melancholy, languid and fierce. He looked like a man who had passions, secrets, and private harrowing griefs and adventures. His voice was rich and deep. He would say it was a warm evening, or ask his partner to take an ice, with a tone as sad and confidential as if he were breaking her mother's death to her, or preluding a declaration of love. He trampled over all the young bucks of his father's circle, and was the hero among those third-rate men.
Having a faithful and generous friend in William Dobbin, George does not appreciate him. Furious with Dobbin for telling the regiment about Amelia, George soon forgets his anger, borrows money from Dobbin to buy Amelia a gift, but purchases a pin for himself.
George courts the acquaintance of the nobility, as all true inhabitants of Vanity Fair, but he does not tell tales on ladies. Self-centered and selfish, he takes Amelia's love and loyalty as his due, and under Dobbin's pressure marries her. When disinherited, he blames Dobbin and says he has lost his money over stupid sentiment. But when his sisters talk against Amelia, he comes to her defense in spite of their glares and his father's anger.
Infatuated with Becky, George asks her to run away with him, but the Battle of Waterloo intervenes. When George realizes he is going into battle and may never see Amelia again, he is overcome with remorse and charges William Dobbin to care for her. As an excuse for George's irresponsibility Thackeray points out that old Osborne's attitude has been lenient toward all sorts of the wildness that George displays. Old Osborne objects only to gambling, and George gambles on the sly.
While Amelia considers George's death the greatest tragedy that could befall her, the reader realizes that, had he lived, her life would have been more sad. At times George rises to heroic proportions, as when he stands up for Amelia against his family. His inconsistency of character: The willingness to defy others in his beloved's behalf and also his willingness to betray her, mark his citizenship in Vanity Fair.