- The protagonist of the story. Hieronimo starts out as a loyal servant to the King. He is the King's Knight-Marshal and is in charge of organizing entertainments at royal events. At the beginning of the play, he is a minor character, especially in relation to Lorenzo, Balthazar, and Bel-Imperia. It is not until he discovers his son Horatio's murdered body in the second Act that he becomes the protagonist of the play. His character undergoes a radical shift over the course of the play, from grieving father to Machiavellian plotter. After his son's murder, he is constantly pushes the limits of sanity, as evidenced by his erratic speech and behavior.
in-depth analysis of Hieronimo.
- The main female character of the story. Bel-Imperia's role is prominent in the plot, especially toward the end. The daugher of the Duke of Castile, she is headstrong, as evidenced by her decisions to love Andrea and Horatio, both against her father's wishes. She is intelligent, beautiful, and, in moments of love, tender. She also is bent on revenge, both for her slain lover Andrea and for Horatio. Her transformation into a Machiavellian villain is not as dramatic as Hieronimo's, but only because she shows signs of Machiavellian behavior beforehand—her decision to love Horatio, in part, may have been calculated revenge, undertaken in order to spite Balthazar, Andrea's killer.
in-depth analysis of Bel-Imperia.
- One of Horatio's murderers. Lorenzo's character remains fairly constant throughout the play. He is a proud verbal manipulator and a Machiavellian plotter. A great deceiver and manipulator of others, Horatio unsurprisingly has an enthusiasm for the theater. Lorenzo has a foil in Horatio; they are both brave young men, but Horatio's directness, impulsiveness, and honesty, contrast and highlight Lorenzo's guardedness, secretiveness, and deception.
in-depth analysis of Lorenzo.
- The prince of Portugal and son of the Portuguese Viceroy. Balthazar is characterized by his extreme pride and his hot-headedness. This pride makes him kill Horatio along with Lorenzo, and it turns him into a villain. He kills Andrea fairly, though with help, so it is unclear whether he is as "valiant" as the King and others continuously describe him. But his love for Bel-Imperia is genuine, and it is this love that primarily motivates his killing of Horatio.
- The proud, promising son of Hieronimo. Horatio sense of duty and loyalty is shown in his actions towards Andrea, and he gives Andrea the funeral rites that let the ghost cross the river Acheron in the underworld. He also captures Andrea's killer, Balthazar, in battle, thus recovering Andrea's body. His sense of pride is shown in his confrontation with Lorenzo; though Lorenzo greatly outranks him in stature, he does not defer, but instead continues to argue his case in front of the King.
Ghost of Andrea
- Andrea's ghost is the first character we see in the play, and the first voice to cry out for revenge. His quest for revenge can be seen both as a quest for justice, since it is sanctioned by Persephone, the Queen of the Underworld, and as a quest for closure. Andrea is denied closure when he travels to the underworld, because the three judges there cannot decide where to place him; ironically, at the end of the play he becomes a judge himself, determining the places of the various characters in hell.
- Andrea's companion throughout the play. Revenge is a spirit that symbolizes the forces of revenge that dominate the play's action. He talks of the living characters as if they were performing a tragedy for his entertainment.
- Hieronimo's suffering wife, her inaction is a foil to his and Bel-Imperia's action. Her inaction, along with her visions of a dead Horatio, torment her increasingly throughout the play, providing an extreme version of Hieronimo's more subdued madness. Her death by her own hand foreshadows Hieronimo's suicide.
- The King of Spain is an ambivalent character. At times he appears noble and is definitely a friend to Hieronimo, resisiting Lorenzo's attempts to have the Knight-Marshal dismissed. But he is also complacent (a typical English stereotype about the Spanish), as demonstrated by his callous conversation after the Spanish victory in Act I, his subsequent dialogue with the ambassador, and his failure to know that Horatio has been murdered on his estate.
- The King's counterpart in Portugal. The Viceroy is shown as both a loving father but also a weak king. He is defeated in battle, wallows in self-pity when he believes his son Balthazar to be dead, is easily led astray by Villuppo into condemning Alexandro to death, and then renounces his kingship in favor of his son. All of these are signs of bad leadership, especially to an Elizabethan audience.
- Bel-Imperia's servant. Pedringano is easily bribed, and he betrays Bel-Imperia and is one of the gang of four murderers who kill Horatio. In fact, Pedringano seems to have no moral considerations, only following the person whom he thinks can help him most. Ironically, this leads him to trust Lorenzo, who ends up betraying him.
- Balthazar's manservant who, along with Lorenzo, Balthazar, and Pedringano, kills Horatio. Lorenzo suspects Serberine of informing Hieronimo of the crime, and has him killed by Pedringano.
- An old man. Bazulto visits Hieronimo because his own son has been murdered, and he wants the Knight-Marshal's help in finding justice. The appearance of the old man makes Hieronimo feel ashamed at his own inability to avenge Horatio's death.
- The Portuguese Ambassador is the agent of communication between the King and Viceroy. His presence appears purely functional, exchanging information between the Portuguese and Spanish court.
- A Portuguese nobleman who fought at the battle in Act I. Alexandro is betrayed by Villuppo, who falsely informs the King that Alexandro has shot Balthazar, the King's son. Alexandro's character appears exceptionally just; even when Villuppo is discovered, he begs the Viceroy (unsuccessfully) for mercy on Villuppo's behalf.
- A nobleman who, for no reason clear to the audience, betrays Alexandro. Villuppo's role is so short and so tied in with his lie about Alexandro that he almost serves as a personifcation of deceit, contrasting against Alexandro's personification of honor.
General of the Spanish Army
- The General simply describes the battle between Spain and Portugal in Act I. His account of Andrea's death (or lack of account of it) and description of the Spanish casualties as minimal provides an ironic contrast to Andrea's lamenting of his death in battle.
- A servant who attends on Bel-Imperia while she is kept prisoner by Lorenzo.
- The hangman is witty and jovial, and he exchanges verbal retorts with Pedringano before hanging him. Later, the hangman discovers the letter on Pedringano's body that confirms Hieronimo's suspicions of Lorenzo and Balthazar's guilt.
- The page is a messenger boy who brings Lorenzo's empty box to the execution, which is believed to hold a pardon for Pedringano. After the page looks inside, he does not tell anyone that it is empty, out of fear for his own life. This has a distinct impact on the play, since Pedringano's belief that he will be pardoned stops him from exposing Lorenzo as one of Horatio's murderers before it is too late.