When many people think of the term hero as it relates to literature, they think of classic Greek mythology. The heroes in this type of literature all typically share certain character traits. They were usually of royal birth, half gods, or otherwise usual. They performed extraordinary feats and sometimes possessed supernatural powers. They almost always had an ideal character that would have been perfect but for one fatal flaw. These characters tended to suffer both physically and mentally as they wound their way through a great journey. Many times, these characters fought for their own honor or the honor of their communities only to die in a strange and unusual way.
Many of these traits fit Othello. He is of a very different birth than his fellow men because he is a Moor. He performs many extraordinary feats in battle and is honored for his personal performance. His journey takes him from war, to meet a young woman and back to war again. We see his internal struggles with jealousy (perhaps his fatal flaw) and his physical struggles with seizures and epilepsy. Othello's journey is not plauged by the supernatural gods but rather by a sadistic Iago manipulating his thoughts. Othello attempts to defend his personal honor but ends up killing innocent victims. Thus, he takes his own life in penance.
Yes, Othello is considered a tragedy, but we can see many of the classic character traits of a hero and a hero's journey woven though out the story. Othello leaves us with many interesting points to consider about human nature just as the great works of ancient Greece did. Many of those works also have elements of a tragedy. The heroes of classic literature rarely found peace and happiness like so many of our modern heroes seem to.