It is the middle of the night, and Roderigo is furious that Desdemona, the beautiful daughter of Brabantio, has eloped with Othello, the Moorish general of Venice. Iago, whom Roderigo has paid to help him court Desdemona, assures Roderigo that he hates Othello, as Othello chose Cassio for his lieutenant and appointed Iago to the low-ranking post of ancient. Hoping to incriminate Othello, Iago and Roderigo wake Brabantio and warn him that Desdemona has been captured and married to Othello.
Meanwhile, the Duke of Venice has summoned Othello to discussthe impending Turkish attack on Cyprus. Brabantio finds Othello and follows him to the Duke, hoping to accuse Othello before the senate. Once there, however, Othello recounts how he won Desdemona's heart through stories of travel and war. Desdemona arrives to defend her choice, convincing both the Duke and her father of her love. When the Duke sends Othello to Cyprus, Desdemona insists on accompanying her husband, along with Iago, his wife Emilia, Cassio and Roderigo.
Once in Cyprus, Iago begins working to incriminate Desdemona before her husband. Hoping to employ Roderigo in this plot, Iago assures him that Desdemona will soon tire of Othello's love and seek satisfaction with Cassio.
At a party that evening, Iago gets Cassio drunk and sends Roderigo to pick a fight with him. In a drunken rage, Cassio loses control, brawling with Roderigo and forcing Othello to break up the fight.Once Othello leaves, Iago convinces Cassio that the only way to restore his reputation is to persuade Desdemona to defend his honor.
The next day, Desdemona, after speaking with Cassio, begs Othello to forgive Cassio and restore his position. Iago, eager to arouse Othello's suspicion, suggests to Othello that Cassio and Desdemona are having an affair. Later, Desdemona finds Othello upset and offers him her handkerchief, but he says it is too small and lets it drop. Emilia sees it on the ground and, explaining that Iago has repeatedly asked her to get it, takes Desdemona's handkerchief and presents it to her husband. Immediately after receiving the handkerchief, Iago tells Othello that he has seen Cassio with it. Viewing the handkerchief as proof, Othello believes Iago'sstory and vows vengeance against his disloyal wife.
Iago then plants Desdemona's handkerchief in Cassio's room.When Othello confronts Desdemona and asks for the handkerchief,she is unable to find it but continues to plead for Cassio's restoration, further enraging Othello. Having found the handkerchief in his room, Cassio gives it to Bianca, a prostitute he has met,asking her to copy out the embroidery in it.
Mad with suspicion, Othello falls into an epileptic fit. Iago consoles him, and, hearing Cassio approach, tells Othello to hide while he probes Cassio about Desdemona. Without letting Othello hear, Iago mentions Bianca to Cassio. Cassio brags, leading Othello to believe that he is boasting about Desdemona. Just as he is boasting, Bianca returns with the handkerchief, furious that Cassio has given her another woman's possession. Seeing the handkerchief in Bianca's hand, Othello is now fully convinced of his wife's infidelity.
That night, Othello furiously accuses Desdemona of being a whore,despite her affirmations of innocence. He orders Desdemona to send Emilia away and wait for him in bed later that night.
Meanwhile, Iago positions Roderigo to ambush Cassio, but Cassio wounds Roderigo instead. Under the cover of darkness, Iago secretly wounds Cassio and then, acting as Cassio's defender, slays Roderigo.
Othello then goes to Desdemona's bedchamber where he again accuses her. Desdemona pleads with him, but, mad with rage, Othello suffocates her. Coming to deliver news of Roderigo's death, Emilia discovers the horrible scene and screams, alerting all in the vicinity of Desdemona's death. When Othello tells them of the handkerchief, Emilia realizes what her husband has done and reveals Iago's plot to the gathered crowd. Enraged, Iago stabs Emilia. Once Iago is caught, Othello wounds him, asks Cassio for forgiveness, and finally stabs himself with a sword he has kept hidden, kissing his murdered bride as he dies.