The setting is Venice, Italy. Act I begins in medius res, or in the middle of the action. The first three lines imply that Roderigo has been giving Iago money, but we don't know for what. Their conversation goes right into how much they dislike Othello. Roderigo is angry with Iago for neglecting to tell him about Othello and Desdemona's elopement. We learn that Iago is angry that Othello passed him up for the position of lieutenant choosing Michael Cassio instead. Iago then insults Cassio by saying that he is book smart but knows nothing of battle. Iago tells Roderigo that he is serving the Moor to get what he wants: "In following him, I follow but myself." We do not yet know Iago's motives. This act, as the others, is full of animal imagery to illuminate the theme of racism. The Moor, Othello, is a black man leading many white men in battle. He is respected, but not really trusted because of the color of his skin; he is still seen as a barbarian. On top of that, he married a well to do white woman.

The action moves next to outside Brabantio's, Desdemona's father's, house. Iago orchestrates a plan in which Roderigo will make a big scene in order to tell her father that Desdemona has eloped with Othello. Take note of the animal imagery and racism in this section. Iago's language is crude. Roderigo says his daughter has been stolen, and this makes Brabantio angry. At this point Iago slips away, so Othello won't know he played a part in telling Desdemona's father about the marriage. Brabantio takes his men out to capture The Moor, intending to throw him in jail.

In scene ii, Iago tells Othello that he wants to beat up the man who caused all of this trouble. Playing both sides, he warns Othello of the senator's power, which makes it seem as if he is looking out for Othello's best interests; the audience knows he is not.

When Othello is confronted by Brabantio and his men, Othello remains extremely calm and in control. This will contrast with his loss of control at the end of the play. The scene ends with Brabantio accusing Othello of enchanting his daughter calling him "devil" and further accuses him of kidnapping, black magic, and more. The men all head over to see the Duke to try to sort out the truth and allow the Moor to defend himself. Ironically, the Duke has already called for Othello because he is in need of his superb military leadership. A Turkish fleet is heading toward Cyprus.

In scene iii the audience sees the respect these men have for Othello. He is called 'the valiant moor" and "brave". We then hear the story of how Othello and Desdemona fell in love. Notice how Othello's speech is poetic and beautifully spoken whereas Iago's speeches are calculated and carefully measured. The audience learns that Othello had been invited to Brabantio's home many times, and this is where he met Desdemona. When he is finished even the Duke admits that such a story would win over his daughter as well. The Duke tells Brabantio that his son-in-law is "more fair than black."

Desdemona is brought in to speak in front of the men. She is a strong woman and handles herself very well. It is decided that she will accompany Othello to Cyprus. As the strong woman she is, Desdemona does not wish to wait at home passively for Othello to return. She wants to accompany him. She is, in a sense, a soldier herself.

At this point the play turns back to Roderigo and his weeping over Desdemona's marriage. He tells Iago he wants to commit suicide, but Iago craftily changes his mind. He tells Roderigo that Desdemona will tire of the Moor soon enough and that he should be ready to swoop in when that happens. After Iago's persuasive speech, Roderigo has decided that this marriage will not last forever, so he will save his money and wait for his time to be with Desdemona.

Act I ends with a famous soliloquy from Iago. In it we learn that he believes Othello has slept with his wife, although he has no proof. He then plots about how he will get Cassio's place as lueitenant. Since Cassio is a handsome man, Iago plans to make Othello think that Desdemona is having an affair with him. The way Iago speaks to the audience is a big draw to this play. We, as an audience, are the only ones he confides in.