Katherine Marie Heigl, born on November 24, 1978, is an American actress. She is best known for her role as Dr. Izzie Stevens on Grey's Anatomy and her starring role in the movies Knocked Up, Zyzzyx Road, 27 Dresses, The Ugly Truth, Killers and Life As We Know It. Heigl started her career as a child model with Wilhelmina Models before she turned her attention to acting. She made her debut in the coming-of-age film, That Night. Heigl co-starred as Isabel Evans in the television series Roswell and movies including My Father the Hero before landing her break out role in Grey's Anatomy.