Major Characters:

1. Duke Vincentio: He is the Duke of Vienna. He pretends to leave the city. He disguises himself as a friar to watch how Angelo rules.
2. Angelo: He is the Duke’s strict deputy. He enforces harsh laws. He desires Isabella and acts hypocritically.
3. Isabella: She is Claudio’s sister. She is about to become a nun. She faces a moral dilemma when Angelo asks her for something in return for her brother's life.
4. Claudio: He is Isabella’s brother. He is sentenced to death for getting Juliet pregnant before marriage.
5. Mariana: She was engaged to Angelo. He abandoned her. She helps the Duke’s plan with the "bed trick."
6. Escalus: He is a wise lord. He advises Angelo. He believes in mercy and justice.
7. Lucio: He is a talkative gentleman. He gossips and often acts foolishly.
8. Juliet: She is Claudio’s fiancée. She is pregnant with his child.
9. Mistress Overdone: She runs a brothel in Vienna. She represents the city’s immorality.
10. Pompey: He is a clown and servant to Mistress Overdone. He adds humor to the play.
11. Provost: He is the prison officer in charge. He sympathizes with Claudio and helps the Duke.
12. Elbow: He is a silly constable. He speaks incorrectly and provides comic relief.

Minor Characters:

1. Friar Thomas: He helps the Duke disguise himself.
2. Friar Peter: He helps the Duke at the end of the play.
3. Justice: He works with Escalus and upholds the law.
4. Barnardine: He is a long-time prisoner. He refuses to be executed.
5. Abhorson: He is the prison executioner.

Non-speaking Characters:

1. Officers, Lords, and Attendants: These characters help create Vienna's background. They follow orders and perform small tasks.