Chellsie Marie Memmel (born June 23, 1988) is a retired American artistic gymnast. She is the 2005 world all-around champion (the third American woman, after Kim Zmeskal and Shannon Miller, to win that title) and the 2003 world champion on the uneven bars. She was a member of the United States women's gymnastics team at the 2008 Olympics.
With a total of seven World Championship and Olympic medals, Memmel is tied with Shawn Johnson as the seventh most decorated U.S. female gymnast, behind Simone Biles (30), Shannon Miller (16), Nastia Liukin (14), Alicia Sacramone (11), Aly Raisman (10) and Dominique Dawes (8).
Chellsie Marie Memmel was born in West Allis, Wisconsin, to Andy and Jeanelle Memmel. Both of her parents were gymnastics coaches, and they encouraged her to play around in the gym and taught her basic skills. When she was eight years old, she started training with Jim Chudy at Salto Gymnastics.