Strug was trained by the legendary coach Bela Karolyi, and joined the United States national team in 1991. In 1992, at age 14, she won a team bronze medal at the Barcelona Olympics, at which she was the youngest member of the entire U.S. delegation. Karolyi retired after the 1992 Games, and Kerri was forced to switch gyms multiple times. 1994 was supposed to be her comeback year, but at a small competition in Arizona, she lost her grip on the uneven bars and flew off them backwards, landing on her stomach on the mat with her legs flipped over her head. She curled up on the mat, gasping and struggling to breathe from the pain, and was carried out of the gym on a stretcher. The injury turned out to be a badly pulled back muscle, which required extensive rehabilitation; but impressively, she recovered in time for the 1995 World Championships, where she was a member of the bronze-medal-winning U.S. team. Karolyi came out from his retirement, and Kerri returned to his gym to prepare for the 1996 Centennial Olympic Games in Atlanta.

Her shining moment came during these Games, as a member of the U.S. women's team, often referred to as the Magnificent 7 for their incredible talent and depth. In the team competition, an event dominated by the Russians for decades and never won by the United States, the U.S. and Russian teams battled neck and neck. The event came down to the final routine on the second and final day of the team competition, July 23.

With a record 40,000 spectators packed in the Georgia Dome for an early afternoon meet (the meet was held in the early afternoon to comply with requests of the European Broadcast Union), the United States had turned in a nearly flawless performance that had the seemingly invincible Russians on the brink of defeat. In the final rotation, the U.S. women had already achieved a convincing victory due to their wide margin of the Russian team, but those on the floor believed that the U.S. team still needed a single good score on the vault to win gold. But Strug's teammate Dominique Moceanu fell on both of her vaults, registering poor scores. Strug, who up to that point in her career had been overshadowed by better-known teammate Shannon Miller, was the last to vault for the United States.

Like Moceanu, Strug fell on her first attempt, and stood up, shaking out her ankle, which she had wrenched in her fall. She limped to the end of the runway for her second attempt. In a moment that would become one of the most famous of those Olympic Games, she landed the vault perfectly on one foot, sealing the women's team gold with a lofty score of 9.712. Strug raised her arms after her vault, saluting the judges, hopped around and raised them again, then collapsed in agony to the mat, grasping her ankle. Karolyi hurried over and carried her off, to thunderous applause from the home crowd. She was helped onto the podium to join her team for the medal ceremony, after which she was treated at a hospital for two torn ligaments in the ankle. Due to her injury, she was unable to compete in the individual all-around competition or the vault finals, despite having qualified for both.

Strug became a national sports hero for her courageous finish, visiting President Bill Clinton, appearing at various television talk shows, making the cover of Sports Illustrated and appearing on a Wheaties cereal box with other team members. ESPN's This is SportsCenter ad campaign poked fun at her injury with two ads featuring various ESPN workers carrying her around.

Shortly after her feat, Strug participated in the Ice Capades and Disney's World On Ice, then announced her retirement and enrolled in UCLA. As a professional, she could not compete in NCAA gymnastics events, so she worked for a time as team manager instead, a behind the scenes role. She later transferred to Stanford.

After graduation, Strug worked as an elementary school teacher in the San Francisco area before moving to Washington, DC, in 2003.

She worked as a staff assistant with the U.S. Office of Presidential Student Correspondence, moved to a job at the Office of the General Counsel in the Treasury Department, and in March 2005, joined the Justice department's Office of Juvenile Justice and Delinquency Prevention staff as a presidential appointee. Strug has also been an active marathon runner, having run marathons in Houston, New York, and Boston.