Mary Lou Retton (born January 24, 1968 in Fairmont, West Virginia) is an American gymnast. She was the first gymnast outside of Eastern Europe ever to have won the Olympic all-around title.

Inspired by watching Nadia Comăneci on television, Retton took up gymnastics. She grew to become the strongest American gymnast in 1983, but missed the World Championships in that year due to an injury.

Shortly before the 1984 Summer Olympics in Los Angeles, Retton again was injured, but she recovered just in time. In the competition - which was boycotted by most East European nations, except for Romania - Retton engaged in a close battle with Ecaterina Szabó of Romania for the all-around title, to the delight of the patriotic audience. Trailing Szabó with two events to go, Retton performed two flawless exercises to win the title by just 0.050.

At the same Olympics, Retton won four more medals: a silver in the team all-around and the horse vault, and bronzes in the floor exercise and uneven bars. For her performance, she was named Sports Illustrated magazine's "Sportswoman of the Year".

Retton retired from gymnastics the following season. She is now married with four daughters, and is a frequent analyst for televised gymnastics.