This is an interesting question, because people usually see Antigone as the tragic figure of the work. In some ways, Creon can be see as tragic as well. In order to make this point, I will give a definition of tragedy by Aristotle and then show how Creon can fit that definition.
In the Poetics of Aristotle, he writes the following as a definition of tragedy:
“Tragedy, then, is an imitation of an action that is serious, complete, and of a certain magnitude; in language embellished with each kind of artistic ornament, the several kinds being found in separate parts of the play; in the form of action, not of narrative; with incidents arousing pity and fear, wherewith to accomplish its katharsis of such emotions..."
Based on this definition, we can say that Creon fits many of the qualification of a tragic hero. His course of action is serious and complete. He decrees that the body of Polynices must not be buried. He also arouses pity and fear at the end of the play, because he realizes that he acted in foolishness. He finally has a change of heart and will let Antigone live. However, he comes to this conclusion too late. Antigone has already killed herself. Now Creon must live with his actions. We can also say that Creon was filled with hubris, because he was unyielding until the end.