Act 4. Desdemona's room. Evening.

Desdemona waits for Otello as she was told to. Filled with foreboding, she asks to be buried in one of her wedding veils. She sings a sad song that her mother's maid Barbara used to sing, when she was abandoned by her lover. It is the Song of the Willow she sang as she sat weeping in a strange land, that the sad willow would form her garland. She ends with the words 'He was born for glory, I to love him.' She then prays to the Virgin Mary to intercede for her ('now and in the hour of our death'), before going to sleep.Otello enters. He makes sure that Desdemona has made her confession since he does not want to destroy her soul. She tries to defend herself and begs him to bring in Cassio. But Otello refuses to listen to her or delay any longer. He strangles her.

Emilia returns with the news that Cassio has killed Roderigo. Before she dies, Desdemona tries to take the blame for her own murder. Emilia cannot convince Otello that Desdemona was innocent. He threatens Emilia so she calls for help. Iago tries to silence her but when the truth emerges he refuses to justify himself. Otello accepts that his career, his glory and his life are over. He stabs himself and in a last effort to kiss Desdemona he dies.