The play begins with two pairs of brothers in conflict: Duke Senior and Duke Frederick, and Oliver and Orlando. Duke Frederick has usurped the throne of his older brother and rightful heir, Duke Senior, and has banished him with several companions to live in the Forest of Arden. Two of the Dukes’ lords, Oliver and Orlando, have recently lost their father. Oliver, Orlando’s older brother, has withheld Orlando’s inheritance and treated him like a servant.
Meanwhile, two best friends - Rosalind, Duke Senior’s daughter, and her cousin Celia, the daughter of Duke Frederick - meet Orlando who has arranged to wrestle with the court champion, Charles. Oliver leads Charles to understand he should beat Orlando easily and suggests that if Charles harmed Orlando, Oliver would be pleased. Orlando, however, defeats Charles and wins the heart of Rosalind.
Duke Frederick admires Orlando’s achievement – until he learns Orlando is the son of Sir Rowland, a friend of Frederick’s banished brother. Frederick leaves and Oliver, overheard by Orlando’s elderly servant, Adam, vows to harm Orlando. Warned by Adam, Orlando flees with him to the safety of the Forest of Arden. Frederick returns to banish Rosalind who now reminds him too much of his banished brother. Celia decides to flee her ruthless father and join Rosalind. With the loyal fool Touchstone, they seek the shelter and safety of the Forest. Because it is dangerous for young women to travel alone, Rosalind disguises herself as a young man, Ganymede, and Celia chooses to dress as a country maid, calling herself Aliena.
Once in the forest, the travelers, with help from the shepherds Corin and Silvius, purchase a cottage, field and sheep and begin their new life. Elsewhere in Arden, Jaques, one of the lords who attends Duke Senior, indulges his melancholy ways until he chances to meet Touchstone. Duke Senior and his followers meet Orlando who comes to them demanding food. When Duke senior learns Orlando is the son of his old friend Sir Rowland, he welcomes Orlando and Adam heartily.
Meanwhile, Duke Frederick is enraged when he learns that Orlando has run away. He orders Oliver to find Orlando and bring him back to the castle or forfeit his property and be banished himself.
Now safely with Duke Senior, Orlando is left to think about Rosalind. He writes poetry about her and hangs it on trees in the forest. Rosalind and Celia (now Ganymede and Aliena) both find the verses and realize the author is Orlando. Rosalind resolves to tutor Orlando in the ways of proper love and urges him to pretend “he” (Ganymede) is really his Rosalind on whom to better practice his wooing.
Love is alive elsewhere in the Forest. Touchstone has found a shepherdess, Audrey, to woo, and Rosalind witnesses the attempts of Silvius to entice another shepherdess, Phebe. Much to Rosalind’s dismay, however, Phebe is attracted to “Ganymede.” When Phebe decides to write a love letter to “him,” she asks Silvius to deliver it. Rosalind receives the letter while she is waiting for Orlando to arrive for a love lesson. It is Oliver who arrives, however, with a tale explaining Orlando’s absence. Orlando had happened on the sleeping Oliver who was being threatened by a lion. Orlando saved Oliver and killed the lion but was wounded in the encounter. At Orlando’s request, Oliver brings a bloody handkerchief as proof. When “Ganymede” swoons at the sight, Oliver realizes it is Rosalind but promises to keep her secret.
The encounter with Orlando and the lion has converted Oliver completely and has reconciled the brothers. Oliver confesses to Orlando that he has fallen in love with “Aliena” and that they will marry the following day. Orlando laments to “Ganymede” that he cannot marry his Rosalind. “Ganymede” declares that, with the help of magic, all will be made right on the wedding day. Then, in the presence of Duke Senior and his lords and other guests, Rosalind reveals herself to Orlando. With much rejoicing, Orlando and Rosalind, Oliver and Celia, Touchstone and Audrey, Silvius and Phebe all wed. Then, as if by fate, the second son of Sir Rowland appears and declares that Duke Frederick has been converted by an encounter with a religious man and has abdicated to Duke Senior, returning to him and his followers all that had been taken from them.