An executioner. As probation for being a pimp, Pompey is assigned to be Abhorson's helper. It is Abhorson's job to execute Barnardine, which he fails to do because Barnardine is drunk, unrepentant, refuses to be executed and is therefore unprepared for heaven. He also fails to execute Claudio when Ragusine's head is substituted for Claudio's.
ANGELO
A learned and morally upright citizen of Vienna, Angelo was originally betrothed to Mariana, but he forsook her when her brother Frederick drowned at sea with her dowry. Duke Vincentio, wishing to have Vienna's laws against fornication enforced but not by himself, appoints Angelo governor while he, unbeknownst, disguises himself as a friar to observe what happens. Angelo orders brothels to be torn down and has Claudio arrested and sentenced to execution for impregnating Juliet. However, when Isabella meets with Angelo to plead for Claudio, Angelo is aroused by her virtue and attempts to seduce her, promising to pardon Claudio in return for her yielding her virginity to him. At the disguised Duke's direction, Isabella agrees but performs a "bed trick," substituting Mariana for herself. Angelo, thinking he has bedded Isabella, orders Claudio executed anyway to hide his misdeed. Isabella and Mariana, again at the Duke's direction, reveal everything to the "returning" Duke, who publicly disgraces Angelo and forces him to marry Mariana. The Duke orders Angelo to be executed, but relents when Isabella pleads for him.
BARNARDINE
A prisoner, set to be executed. Born in Bohemia but raised in Vienna, Barnardine has been a prisoner for nine years. Frequently drunk, he expresses no concern about being executed. When Abhorson and Pompey come to execute him, Barnardine refuses to participate and returns to his cell. Duke Vincentio initially plots to have him executed in place of Claudio to trick Angelo, but drops that plan because Barnardine is not yet ready for heaven. He is not needed when Ragusine, who better resembles Claudio, dies of a fever. In the end, the Duke pardons Barnardine and places him in Friar Peter's custody.
CLAUDIO
A young gentleman of Vienna, imprisoned and set to be executed for impregnating his legitimate but secret wife Juliet. The brother of Isabella, Claudio has Lucio take her to plead with Angelo on his behalf. When Angelo propositions Isabella, promising to free Claudio in exchange for her yielding her virginity to him, Claudio unexpectedly urges Isabella to do so. After Angelo has intercourse with Mariana, believing her to be Isabella, he orders the execution of Claudio anyway. But the disguised Duke Vincentio persuades the Provost to trick Angelo by substituting the head of Ragusine for Claudio's. In the end, the Duke has the still living Claudio revealed and pardons him.
CRASSUS
A "ghost character." A lord of Vienna and friend to Duke Vincentio. When the Duke decides to "return" to Vienna in his own guise, he has Friar Peter deliver letters to Crassus, Flavio, Valentinus, and Rowland, telling them to meet with him.
DUKE VINCENTIO
The governor of Vienna, the Duke wishes to have the city's laws against fornication enforced but not by himself. Instead, he appoints Angelo to govern in his place while he secretly disguises himself as Friar Lodowick in order to observe what occurs. Thus disguised, the Duke visits the prison, where he becomes acquainted with Claudio and Isabella. He eavesdrops on them and overhears Isabella relate Angelo's proposition to her: Angelo has promised to pardon Claudio in return for her yielding her virginity to him. The Duke confronts Isabella and tells her that Angelo was once betrothed to Mariana, whom he forsook when her brother Frederick drowned at sea with her dowry. The Duke directs Isabella to agree to Angelo's demands, but to perform a "bed trick, " substituting Mariana for herself. Angelo, thinking he has bedded Isabella, orders Claudio executed anyway to hide his misdeed. The Duke then conspires with the Provost to execute Barnardine in Claudio's place and show Angelo his head as proof of Claudio's execution. When the prisoner Ragusine, who more resembles Claudio than does Barnardine, dies of a fever they decide to use his head instead. Plotting to ensnare Angelo, the still-disguised Duke tells Isabella that Claudio is dead and directs her and Mariana to reveal everything to the Duke when he "returns" to Vienna. In the end, the Duke publicly disgraces Angelo and forces him to marry Mariana, reveals that Claudio is still alive and pardons both him and Barnardine, orders Lucio to marry the prostitute Kate Keepdown as punishment for slandering him and impregnating her, and declares that he will marry Isabella.
ELBOW
A constable. Spouting comical malapropisms, Elbow brings Pompey and Froth before Angelo and Escalus, charging Pompey with prostituting Mistress Elbow to Froth. Angelo grows weary of the proceedings and leaves Escalus to pronounce judgements. Escalus orders Elbow to bring him the six or seven men in Elbow's district best capable of being constables, presumably for the purpose of replacing Elbow.
ESCALUS
An elder lord of Vienna, Escalus is appointed Angelo's second-in-command by Duke Vincentio. Escalus interrogates the accused criminals brought before them and makes decisions in Angelo's absence. In contrast to Angelo, who is a stubborn moral absolutist that issues harsh judgements, Escalus is marked by wisdom, employing mercy and common sense in his decisions. When constable Elbow accuses Pompey of prostituting Mistress Elbow to Froth, Escalus releases them with warnings and indicates that he will replace the clownish Elbow with someone more capable. Escalus disagrees with Angelo's judgement of Claudio, but is loyal to the Duke's order to support Angelo.
FLAVIO
A "ghost character." A lord of Vienna and friend to Duke Vincentio. When the Duke decides to "return" to Vienna in his own guise, he has Friar Peter deliver letters to Flavio, Crassus, Valentinus, and Rowland, telling them to meet with him. The Duke indicates he wants to meet with Flavio before the others.
FRANCESCA
A nun of the order of Saint Clare, an order known for strictness and self-discipline. When Isabella becomes a novitiate in the order, Francesca explains the rules of the sisterhood to her.
FREDERICK
A "ghost character." A renowned soldier who is brother to Mariana. When Frederick drowns at sea with Mariana's dowry, Angelo breaks off his engagement to her.
FRIAR LODOWICK
The disguise assumed by Duke Vincentio that allows him to observe Angelo's governance of Vienna while the Duke is believed absent.
FRIAR PETER
A monk who serves Duke Vincentio. Friar Peter assists the Duke late in the play by delivering his letters to Flavius, Valencius, Rowland, and Crassus. As part of the Duke's trick, Friar Peter later enters as the mouthpiece of Friar Lodowick (the Duke's alter ego). He defends Friar Lodowick against Lucio's slanders and brings Mariana before the Duke to accuse Angelo.
FRIAR THOMAS
A monk who serves as Duke Vincentio's confidant. He agrees that the Duke clearly has the power to "unloose this tied-up Justice when you pleased." It is Friar Thomas who helps Vincentio to disguise himself as a monk and take the identity of one Friar Lodowick.
FROTH
A foolish gentleman of Vienna of "fourscore pounds a year" and frequenter of Mistress Overdone's house. He never willingly enters a tavern, but is "drawn in." Froth and Pompey are brought before Angelo and Escalus, where Pompey is charged with prostituting Mistress Elbow to Froth. Escalus releases Froth with a warning to avoid pimps and brothels.
ISABELLA
The sister of Claudio and a novitiate in the sisterhood of Saint Clare, an order known for strictness and self-discipline. When Claudio is arrested and sentenced to execution for fornication, Isabella (with Lucio's encouragement) pleads with Angelo on her brother's behalf. Angelo, aroused by her virtue, attempts to seduce her, promising to pardon Claudio in return for her yielding her virginity to him. Isabella is horrified when Claudio unexpectedly urges her to do so. Duke Vincentio, disguised as a friar, directs her to agree with Angelo's demand but to perform a "bed trick," substituting Mariana for herself. Angelo, thinking he has bedded Isabella, orders Claudio executed anyway to hide his transgression. The Duke, knowing otherwise, tells Isabella that Claudio is dead. The Duke then directs Isabella and Mariana to accuse Angelo publicly before the "returning" Duke and reveal everything. The Duke orders Angelo to be executed, but Isabella, at Mariana's urging, pleads for Angelo; the Duke relents, reveals that Claudio was not executed, and declares that he will marry Isabella. Isabella's response to Vincentio's offer of marriage is not clearly delineated in the text and is the topic of much scholarly and theatrical debate.
JULIET OR JULIETTA
Listed as Juliet in the dramatis personae, and usually referred to thus, Claudio twice calls her Julietta. She is a young woman secretly married to Claudio per verba de praesenti. When her secret husband, Claudio, legitimately impregnates her, Angelo has them imprisoned for fornication and Claudio sentenced to execution. The disguised Duke counsels her, and though she demonstrates contrition over the act, scholars debate whether she is in fact guilty of a moral crime. As Juliet grows close to delivering the child, she is removed from the prison and presumably taken to a convent to give birth.
KATE KEEPDOWN
A "ghost character." A punk, or prostitute, said to have a child by Lucio, who promised to marry her but did not. In the end, Duke Vincentio punishes Lucio for slandering him by forcing Lucio to marry her, thereby legitimizing the child and making Lucio a cuckold.
LUCIO
Described as a "fantastic," or a playboy, a gentleman who dresses and behaves ostentatiously and flouts social conventions, Lucio is a friend to Claudio and frequents Mistress Overdone's brothel. He is said to have fathered a child by the prostitute Kate Keepdown. When Claudio is arrested for fornication, he sends Lucio to Isabella to ask her to plead with Angelo on his behalf. During Isabella's conference with Angelo, Lucio repeatedly prompts her to try harder to convince Angelo. Later, Lucio visits the prison where he meets and converses with the disguised Duke Vincentio; Lucio slanders the Duke, saying that he failed to enforce the laws against fornication because he was a fornicator himself. In the end, the Duke punishes Lucio by forcing him to marry Kate Keepdown, thereby legitimizing her child and making Lucio a cuckold.
MARIANA
A woman betrothed to Angelo. When her brother Frederick drowned at sea with her dowry, Angelo forsook her. After Angelo propositions Isabella, the disguised Duke Vincentio devises the "bed trick," in which Mariana is substituted for Isabella. In the end, the Duke forces Angelo to marry her.
MISTRESS ELBOW
A "ghost character." Described as being pregnant and craving "stewed prunes" (a likely euphemism for testicles), Mistress Elbow visits Mistress Overdone's brothel, where she has intercourse with Froth. Elbow accuses Pompey of prostituting her. Pompey claims she prostituted herself.
MISTRESS OVERDONE
The keeper of a brothel, she has had nine husbands, "Overdone by the last." Mistress Overdone is imprisoned and the brothel torn down on Lucio's testimony against her. She retaliates by revealing that Lucio fathered a child by the prostitute Kate Keepdown, which she watched over.
POMPEY
A clown character, Pompey works for Mistress Overdone as a tapster and pimp in her brothel. Elbow brings Pompey before Angelo and Escalus, accusing him of prostituting Mistress Elbow to Froth. Pompey defends himself by claiming that she prostituted herself. Escalus releases Pompey with a warning never to be brought before him again, though Pompey clearly does not heed it as he is again arrested by Elbow and sentenced to probation as assistant to the executioner Abhorson. Pompey observes that the prison is very like the brothel because Mistress Overdone's former clients are now there.
PROVOST
The keeper of the prison where Claudio is kept. Though the Provost disagrees with Angelo's punishment of Claudio, he initially refuses to save him by having Barnardine executed in his place. When the disguised Duke Vincentio convinces him that the Duke would allow it, he finally agrees to the trick. Instead of substituting Barnardine, however, who refuses to be executed, they take the head of Ragusine, a prisoner who dies of a fever.
RAGUSINE
A "ghost character." A pirate imprisoned in Vienna who dies of a fever. Because of his resemblance to Claudio, the Provost and the disguised Duke Vincentio substitute Ragusine's head for Claudio's, tricking Angelo into thinking that Claudio has been executed.
ROWLAND
A "ghost character." A lord of Vienna and friend to Duke Vincentio. When the Duke decides to "return" to Vienna in his own guise, he has Friar Peter deliver letters to Rowland, Crassus, Flavio, and Valentinus, telling them to meet with him.
VALENTINUS
A "ghost character." A lord of Vienna and friend to Duke Vincentio. When the Duke decides to "return" to Vienna in his own guise, he has Friar Peter deliver letters to Valentinus, Crassus, Flavio, and Rowland, telling them to meet with him.
VARRIUS
A lord of Vienna and friend to Duke Vincentio. When the Duke decides to "return" to Vienna in his own guise, he sends for Varrius, who comes to meet with him. The consummate "walk-on" rôle, Varrius enters at the end of IV.v only to have Vincentio welcome him and then immediately exit with him. He has no lines.