Chellsie Marie Memmel (born June 23, 1988 in West Allis, Wisconsin) is a retired American gymnast. She is the 2005 World All-Around Champion, making her the third American woman, after Kim Zmeskal and Shannon Miller, to become World Champion in the All-Around. She is also a World Champion on the uneven bars (2003) and as part of the U.S. team (2003). She is a member of the United States' 2008 Olympic women's gymnastics team.
With a total of seven World and Olympic medals, Memmel is tied with Shawn Johnson as the fifth most decorated U.S. female gymnast in history behind Shannon Miller (16), Nastia Liukin (14), Alicia Sacramone (11), and Dominique Dawes (8).