Prospero
Prospero is Miranda's father, the usurped Duke of Milan and the play's protagonist. He is usurped twelve years before the play takes place by his brother, Antonio, alongside the king of Naples, Alonso. As a result of his usurping, he and Miranda are forced to flee Milan by boat, aided by Gozalo. He and Miranda live on an island wherein he practices magic in order to exact revenge on his brother.
In Taymor's film version, Prospero is cast as 'Prospera', the wronged widow of the Duke of Milan, meaning Miranda has a mother instead of a father.
Miranda
Miranda is Prospero's daughter. Having been raised on the island from a very young age, the only men she has ever known are her father and their slave, Caliban. Miranda's lack of contact with others leads her characterization to be naive yet open-minded. She is very loyal to her father and arguably the most optimistic of all the play's characters.
Caliban
Caliban is an original inhabitant of the island that Prospero and Miranda live on. He is the son of the deceased witch, Sycorax, and believes that Prospero has stolen the island from him. Prospero justifies his enslavement of Caliban with the accusation that Caliban tried to rape Miranda.
Ariel
Ariel is one of Prospero's servants. Sycorax had imprisoned Ariel inside a tree, and that is where Prospero finds him upon coming to the island. Prospero releases Ariel under the condition that he serve him until Prospero decides to grant him freedom. Ariel is a magical being, able to change his form and travel at great speeds.
Ferdinand
Ferdinand is Alonso's son and heir. When Ferdinand and others arrive on Prospero's island, he quickly falls in love with Miranda. In order to demonstrate his love, he acts as a servant in order to gain Prospero's approval.
Alonso
Alonso is Ferdinand's father, the king of Naples, and one of the men responsible for usurping Prospero. He regrets his role in usurping Prospero.
Antonio
Antonio is Prospero's brother who usurps him in a demonstration of his hunger for power. Despite his desire to be powerful, he is also foolish and cowardly. Antonio and Sebastian's plot to kill Alonso represents the first of the play's key sub-plots
Sebastian
Sebastian is Alonso's brother and, like Antonio, he is power-hungry while simultaneously cowardly and foolish. We see just how vicious he can be with his tongue in the opening scene of the play, where he attacks the Boatswain whilst he is trying to save the ship in the storm.
Trinculo and Stephano
Trinculo is a jester, and Stephano is a drunkard. The two of them are with each other throughout the entire play, and spend much time with Caliban after separating from the rest of their crewmates. Caliban offers his servitude to them, thankful that he no longer has to serve Prospero. The relationship between Trinculo, Stephano and Caliban forms the second of the two key sub-plots in the play.
Gonzalo
An old lord that helps Prospero and Miranda escape after Prospero is usurped. He provides much background information and commentary throughout the play.