Grace Kathleen Hartzel (born October 11, 1995) is an American fashion model from Zionsville, Indiana. She was discovered at the age of 15 while dining at a St. Louis Cheesecake Factory with her family. She has walked in nearly every major show during the fall/winter 2015 and spring/summer 2016 shows after being noted as a muse of then-YSL fashion designer Hedi Slimane in the fall/winter 2014 show. Slimane's spring 2014 show was entirely made in Hartzel's image, when she was an unknown.