Retton now lives in Houston, Texas. She is married to Houston real estate developer Shannon Kelley with four daughters: Shayla Rae (born 1995), McKenna Lane (born 1997), Skyla Brae (born 2000), and Emma Jean (born 2002).
After winning her second American Cup, the US Nationals, and the US Olympic Trials in 1984, Retton suffered a knee injury that forced her to undergo an operation. However, she recovered just in time for the 1984 Summer Olympics in Los Angeles. In the competition, which was boycotted by the Soviet bloc 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 (after bars and beam) with two events to go, Retton scored perfect 10s on floor exercise and vault to win the all-around title by just 0.05 points.
At the same Olympics, Retton won four additional medals: a silver in the team competition and the horse vault, and bronze in the floor exercise and uneven bars. For her performance, she was named Sports Illustrated magazine's "Sportswoman of the Year" (shared with fellow American Edwinmeany). She appeared on a Wheaties box, and became the cereal's first official spokeswoman. Her small stature led a wag at SPORT magazine to comment that "Her life-size picture now appears on the Wheaties box."
The people in Retton's hometown of Fairmont, West Virginia, were supportive of her Olympic endeavors. A street and park in the town were later named after her. Retton retired from gymnastics after winning an unprecedented third American Cup title in 1985. She later had cameo appearances as herself in Scrooged and Naked Gun 33⅓: The Final Insult.
In 1997, Retton was inducted into the International Gymnastics Hall of Fame.
Retton has won many commercial endorsements, including the first appearance by a female on a Wheaties box. She is also a frequent analyst for televised gymnastics and attended The University of Texas at Austin after the Olympics.
Retton was born with hip dysplasia, a condition that was aggravated by her years as a competitive gymnast. After experiencing increased pain she had hip replacement surgery on her left hip in her mid-30s. Retton also suffered from an overactive bladder and arthritis. She serves as a paid spokesperson for Biomet and for Pfizer to publicize treatment for these conditions.
Retton has a skill named after her on the uneven bars called "The Retton Flip," a transition (front flip) from low- to high-bar, resulting in the gymnast perched or "sitting" on top of the high bar. Because the bars have been pushed further apart in the decades since she first performed that element, it is believed to be no longer possible to perform.
In 2002, Retton starred in the children's televison program, Mary Lou's Flip Flop Shop, a series she created with her husband for PBS. The series was produced by HoustonPBS. Originally slated for 13 episodes, only five episodes aired. Old episodes of the series are still seen in re-runs in some markets and are available on DVD.