Oliver is the eldest son of Rowland du Bois and the brother of Orlando and Jaques du Bois. He is originally intent on killing Orlando, but realizes his error and falls for Celia after being thrown from his estate.
The first scene of the play take place on Oliver's property. Orlando and Oliver get into a tussle over the fact that Oliver refuses to give Orlando his inheritance of 1000 crowns, instead forcing him to stay at his house without education or employment. Oliver then talks with Charles, a powerful wrestler who claims that Orlando is planning to take him on, which may mean that he will die. Oliver, still agiated, conspires against Orlando and tells Charles that he fights dirty and that he is too "young and...villainous" for his life to be feared for. Charles is perfectly reassured, but he is thrown during the wrestling by Orlando. This causes Orlando to run away to Arden with Adam, narrowly escaping Oliver's attempt to burn down his meager lodgings. When Duke Fredrick goes on a hunt for Orlando, he suspects that some of the courtiers are working against him, including Oliver. Despite Oliver's protests, Fredrick ejects him from his estates and tells him that his assets have been siezed by the court until he finds Orlando.
Oliver goes to Arden, where he searches for a while before Orlando finds him. When he is discovered, Oliver is under attack from a snake and a lioness, which Orlando saves him from. Oliver is thankful and resolves to change his ways. Orlando then takes him to Dule Senior, who nourishes him and helps him freshen up. Orlando then reveals that the loness had wounded him in combat. Oliver nurses him quickly back to health, and he sends him to Rosalind and Celia, to relate to them all of this to excuse his promise of returning within an hour, giving Oliver the handkerchief he used as a bandage for proof.
Upon meeting them, Oliver immediately falls for Celia, who also falls for him. Their engagement is sudden, but they both insist (as does Rosalind, who can testify to their first meeting) that their love is genuine. They are originally the only couple to be married in the play's final scene, but thanks to Rosalind, Touchstone, and Audrey, there are three other couples who join them. Upon wedding the two, Hymen remarks that they are "heart in heart."