Antigone can certainly be identified as a tragic heroine in the play by Sophocles that bears her name. By the time the play opens, Antigone has already experienced more than her share of tragedy. She is the child of an incestuous relationship between her parents, Oedipus and Jocasta. They didn't know it when they married, but Jocasta was actually Oedipus's mother. She ended up killing herself. Oedipus blinded himself in grief and anguish. Antigone and her siblings were left shattered.
Antigone then wandered with her blind father for many years, caring tenderly for him. Meanwhile, her two brothers began feuding with each other, and one attacked Thebes in an effort to regain the rule of the city. He has just been defeated when Antigone opens. In fact, both of Antigone's brothers have died in the fight, and King Creon has ordered that the "traitor" Polyneices should be left to rot, unburied on the battlefield.
Antigone will not allow this unjust and compassionless order to stand. She declares that she will bury her brother. She cannot stand to leave him lying there as food for the birds and dogs. She will defy Creon's order even if the price is her own life. And, indeed, she does. Antigone performs the customary rites for her brother as well as she can. When she is caught, she stand courageously and unrepentantly before Creon and accepts her punishment, unjust and horrific as it is, of being buried alive.
Creon actually repents in the end and hurries to release Antigone, but it is too late. She has hung herself to escape the horror of her fate.
Let's think for a moment about the characteristics of a tragic hero or heroine as defined by Aristotle and see how they apply to Antigone. First, a tragic hero or heroine is virtuous and therefore sympathetic to the audience. We can certainly say this of Antigone. She stands up for what is right no matter what the consequences, and we cannot help but admire her for it.
But a tragic hero or heroine is also flawed. Antigone is not perfect. She is stubborn and tries to get her sister to go along with her (playing a pretty good guilt trip in the process). She also gives in to despair at the end of the play and kills herself. Finally, a tragic hero or heroine suffers some kind of reversal of fortune. This is certainly true of Antigone, who has gone from princess and favored daughter to criminal.