Who is the villain in othello?

Iago is, although he is more likely to get others to do bad things than to do them himself. He does murder Roderigo, after egging him on to kill Cassio. He also induces Othello to murder Desdemona.
The villain in Othello is Iago as he twists Othello's mind and gets him to kill Desdemona, steals from Roderigo and kills him, kills Emilia, wounds Cassio and ruins his job.