Simone Biles

Won a record fourth All-Round World Championship and six medals overall despite a kidney stone. Became first female gymnast to medal in each World event in 31 years. Regarded by many as the best of all-time, Biles holds the American record for most gymnastic gold medals at a single Olympic Games (4) and, in addition to her all-around record, she set a record for total World medals (20), as well as the gymnast with the most World gold medals of any gender (14).