Rebecca Sharp
The protagonist of the novel, Becky is a strong-willed young woman obsessed with status and wealth. She attends Miss Pinkerton's academy as an orphan alone in the world, and makes only one friend, Amelia, who is friends with everyone. Rebecca frustrates her classmates and instructors, acting superior to them all. For example, she insists on speaking French when she knows that no one understands her, and demands payment for tutoring her classmates.
As soon as she is out of the school, her manipulations begin. She feigns attraction to Joseph Sedley because she understands the position and wealth a marriage with him would bring. She also appeals to Rawdon Crawley, who ends up marrying her. Sir Pitt, the local baronet, also falls for her. It is clear that men fall at her feet, but she doesn't ever express genuine love for them. She finds Rawdon stupid, sees Sir Pitt only for his status and money, and hates George for his interference in her plan to marry Joseph.
Rebecca is also a compulsive liar. She has an affair with George behind Amelia's back. While she is with Rawdon, she flirts with men of status in order to steal their money, and she tries her best to secure Aunt Matilda's estate by attending to her. As a final act of deceit, Rebecca manages to have Joseph sign an insurance policy of which she is the sole beneficiary, earning her half of what he owned before his death.
Amelia Sedley
Amelia is a good-natured person, and she is easy to like. As a young girl, she makes many friends at Miss Pinkerton's school. Unfortunately, she is easily manipulated and patronized when she emerges into society. George walks all over her, and his sisters are condescending towards her. Regardless, Amelia remains infatuated with George, convinced that he must love her in return. Her innocence is initially framed as something good, but soon the author reveals that this quality is also her tragic flaw. She is a victim of so many things; her family's designs, her family's financial ruin, Becky's ruthlessness, George's indifference, and high society's overall cruelty.
Amelia is nevertheless a determined woman. Her son becomes her obsession, and she fights to keep and provide for him, letting the rest of her family and herself starve and struggle so that he can have nice things. She resolves to commit suicide when he is taken from her, but instead, she spends all her time spying on the boy.
Joseph Sedley
Joseph, or Jos, is Amelia's elder brother and a tax collector in India. He is a relatively wealthy man, and he admires people only based on whether or not they come from a nobility line. He dresses in ridiculous, extravagant clothing and is grossly overweight. Jos' father constantly makes jokes at his expense, which frightens him, just as he is frightened by women, which becomes especially evident when Becky tries to flirt with him and win his hand in marriage.
Jos enters the war as a civilian but dresses in military clothing to impress people. When the war starts, he decides to change back into civilian clothing so that he won't be recognized as a soldier. The sound of bombs frighten him, and he buys horses from Becky at a ridiculous price so that he can escape. His timidity influences every major decision in his life.
Even though his family is at the point of starvation, Jos only sends them a small annual allowance from his paycheck. He refuses to buy his father's wine, even though it will help his business, because he deems the wine inferior. Near the end of the novel, Jos once again finds himself in Becky's snares, and becomes another of her unsuspecting victims.
George Osborne
George is a disrespectful playboy. He is Amelia's love interest and the man she has been promised to since childhood. He is obsessed with the chase and does not seem to have the capacity to love anything other than himself. He gambles, drinks, constantly buys things for himself, and takes advantage of Amelia's feelings for him and of Dobbin's loyal friendship.
Eventually, George marries Amelia partly because she is so touchingly pathetic and partly because it makes him feel generous to be giving the girl her heart's desire. He also seems to derive pleasure from the fact that he is defying his father. George appears on the surface to take his military responsibilities seriously by refusing the comfortable life his father offers him, and as a result, he dies in the Battle of Waterloo.
William Dobbin
George's best friend Dobbin is one of the few characters not consumed by vanity. He is sincere and kind, and he does not expect recognition for his altruism. He is very much in love with Amelia, but he defers to George, and she doesn't even notice his affections for her. He plays an instrumental role in making their marriage possible, but ends up confused about his own gesture, due to his strong feelings for Amelia.
Dobbin is also extremely humble. There are several occasions in the book when he submits to George, even when it is clear that he is in the right. But as often as he encourages George on the right path, at the end of the day, he never truly speaks up for himself.
Sir Pitt Crawley
Sir Pitt is Rebecca's wealthy employer. He is a baronet but has accrued enormous debt over the years and is relying on the beneficiary of his sister's fortune to bail him out when she passes away. He is miserly and cruel and treats his wife with indifference. Furthermore, he has an inappropriate affinity for younger women. The current Lady Crawley is younger than he, and when she dies, he immediately seeks Rebecca's hand in marriage. When she refuses, he moves on to the young Ms. Horrocks, the daughter of his butler.
The end of Sir Pitt's life is spent in embarrassing drunken debauchery. He reveals his true nature when he starts spending all his time with common people, the friends of his servants, and making passes at his butler's daughter. He feels more at ease with this crowd, which makes sense when considering the narrator's commentary on his rough, crude manner at the beginning of the novel.
Young Pitt Crawley
The older son of Sir Pitt, he is one of the contenders for Aunt Matilda's fortune. However, he stands in stark contrast to his irresponsible brother. He is Lady Crawley's favorite and is the only person who pays her any attention. He eventually marries the young Jane Sheepshanks and becomes the heir to Sir Pitt's estate. He treats Rebecca and Rawdon with kindness by inviting them to come stay at his residence.
Eventually, young Pitt Crawley becomes the heir to Aunt Matilda's money and as a result, Rebecca sends her son, Rawdon, to live with him. He turns out to be the most responsible member of the Crawley family and seems to benefit because of it. At the same time, he is a victim of Becky's deceit, since he finds her more intelligent, interesting, and potentially useful than his own wife.
Rawdon Crawley
Rawdon is another of the novel's playboys. He doesn't care about education, and he spends his time fighting duels and gambling. The first honest and honorable thing he does is marry Rebecca, with whom he falls dearly in love, and vows to take care of her. In a gesture of love, he purchases a house and furnishes it with credit, which indicates that he is also financially irresponsible.
Rebecca's reflections make it clear that Rawdon is not very bright and he soon falls victim to her designs. She promises to take care of him and, naively, he takes her word for it. He gambles to earn money, and Rebecca makes sure, using her feminine wiles, that he wins often enough to support them. He eventually lands himself in prison for not paying his debts and when Rebecca doesn't bail him out, he finally becomes suspicious and uncovers all of the fraud she has engaged in over the years with various men. In the end, he walks out on her.
Old Osborne
Old Osborne is George's father. He used to be a friend and beneficiary of Mr. Sedley, but when the Sedleys fall into financial ruin he breaks off all ties with them and encourages his son to abandon their daughter. He also tries to push his son towards a wealthy heiress by encouraging him to forget his military duties and consider joining Parliament.
John Osborne clearly does not have much integrity. He does feel a little remorse at turning his back on the Sedleys, but this does not change his actions. He disowns his son when George decides to marry Amelia, and when George dies he is more worried about appearances than the tragedy itself. Finally, he is willing to wrest a son from his mother when Amelia is in financial trouble, as if exacting revenge for marrying his son.
Lord Steyne
Lord Steyne is a marquis from a long line of wealthy nobles. He ignores his wife and tries to drown his boredom in social gatherings. He has a son, George, who he does not acknowledge because of George's mental illness.
Lord Steyne is one of the many men who falls for Becky's schemes. He finds himself enamored with her and spends many evenings at her home. He gives her money and jewelry, which she hides from her husband. He is quick to believe her lies, because he wants them to be true.