In Sophocles's play Oedipus, Oedipus is a hero who's life ended in tragedy. He continues to try and find the truth even though he knows that the truth may hurt him. He helps the people of Thebes by solving the riddle of the sphinx, saves the city, and becomes king and marries the queen (who unknowingly to Oedipus is his mother). He upholds morals and accepts responsibility for his actions unlike the other people in the play. Oedipus is a hero because he is a truth seeker, he cares about others, and he cares about responsibility and morals.
Oedipus always searches for the truth. Even when everything starts looking like it is going the wrong way for him he continues to go after the truth. He "discovers" the truth about the Riddle of the Sphinx. He is always looking, trying to find what is really true. He goes so far as to threaten a shepherd so the shepherd will tell him the truth.
Unfortunately, his search for truth eventually ended is his downfall. That is how far Oedipus went to search for the truth. He searched for it continually in the play.
Oedipus cares about others, which is shown many times in the play. He leaves the people he believes to be his father and mother to thwart an oracle's prophecy that he would kill his father and marry his mother. He solves the riddle of the sphinx and saves the people of Thebes from disaster. Closer to the end of the story Oedipus leaves the town because he is disgraced and doesn't think the people want to see him at all. These reasons all contribute to the fact that he is full of care about others and that he is a hero.
Oedipus upholds morals and...