Orsino: The duke of Ilyria, Orsino is usually melancholy and in love with being in love. He at first is in love with Olivia, but, upon seeing the hopelessness of that situation and the honesty and beauty of Viola, falls in love with and marries her.
Sebastian: The twin brother of Viola, he is a noble young man who is shipwrecked along with his sister and ends up in Ilyria. At the end of the play, he marries Olivia.
Antonio: A sea captain and true friend of Sebastian, he is a wanted man in Ilyria and thus at first remains in hiding. However, when he surfaces to save who he believes is Sebastian he is arrested, but is later pardoned and released when all the confused identities are sorted out.
A Sea Captain: A friend of Viola
Valentine: A gentleman attending Orsino.
Curio: Another gentleman attending Orsino.
Sir Toby Belch: The uncle of Olivia, he lives in her household and uses her generosity to him as a way to support his life of drink and song. He also takes advantage of Sir Andrew and his money. In the end, he marries Maria, his equal in wit and fun.
Sir Andrew Aguecheek: A rich and foolish knight and "friend" of Sir Toby Belch, he is duped into staying in the household and providing money and drink to Sir Toby.
Malvolio: A steward and foolish suitor of Olivia, Malvolio is the opposite of Sir Toby and Maria. His arrogance with them eventually leads to their tricking him and cruelly locking him in a dark room. In the end, he is the only one unhappy and swears his revenge on the rest.
Fabian: A servant of Olivia.
Feste: A clown and servant of Olivia, he usually participates in Sir Toby’s and Maria’s partying and trickery.
Olivia: A countess, she is in mourning (for seven years!) for her deceased brother. She falls in love with Viola, whom she thinks is a boy, and, in the end, marries her twin, Sebastian, thinking he is the other twin
Viola: Twin sister of Sebastian, she is a strong and capable young woman who dresses as a boy, Cesario, to survive in this strange country. She quickly falls in love with Orsino and later, after he realizes she is a beautiful and intelligent young woman, marries him.
Maria: An attendant of Olivia, she is part of the partying and antics of Sir Toby and the others. She later marries Sir Toby.