Karen Lende O’Connor has competed in five Olympic Games, three World Equestrian Games, and two Pan American Games. In 1993, O’Connor was the number one ranked lady rider in the world and she has been named U.S. Female Equestrian Athlete of the Year 10 times.

O’Connor began competing internationally in the late 1970s and began riding with the U.S. Equestrian Team in 1986 at the World Championships in Gawler, Australia, where she rode Lutin V. In the 1980s she won multiple CCI3* events and rode for the U.S. in the 1988 Olympics in Seoul, South Korea.

During the 1990s, O’Connor and her USEA's Eventing Hall of Fame partner Biko were mainstays of the U.S. team, riding to multiple top-10 finishes at major international events including the Badminton Horse Trials and Rolex Kentucky Three-Day Event. O’Connor rode Biko at the 1994 World Equestrian Games and the 1996 Olympics in Atlanta, Georgia, where they were part of the silver medal team. O’Connor went on to ride Prince Panache at the 1998 World Equestrian Games, where the U.S. team won the bronze medal. Shortly after that, the pair won the 1999 Rolex Kentucky Three-Day Event. At the 2000 Olympics in Sydney, Australia, O’Connor and Prince Panache were members of the bronze medal team.

In the early 2000s, O’Connor found international success with her mount Joker’s Wild, winning the individual silver medal at the 2003 Pan American Games, and with Upstage, whom she competed with at the 2006 World Equestrian Games in Aachen, Germany. O’Connor also found success aboard the 14.1 hand Sport Pony Theodore O’Connor, finishing third at the 2007 Rolex Kentucky Three-Day Event and sixth there again in 2008. At the 2007 Pan American Games, O’Connor and Teddy won individual gold and team gold. O’Connor piloted Mandiba through the 2008 Olympics in Hong Kong, China and then together represented the U.S. at the Alltech FEI World Equestrian Games in Lexington, Kentucky in 2010.

In 2011, O’Connor triumphed in many events with her mounts Veronica and Mr. Medicott. She finished ninth at the 2012 Olympics in London, England with Mr. Medicott, where O’Connor was the highest-ranking U.S. rider at the Games that year. O’Connor was also noted as the oldest Olympian to represent the U.S. in any sport at the London Games, paying tribute to her lifetime fitness programs and dedication to the sport.

On October 6, 2012, O’Connor fell while competing Veronica, suffering burst and compression fractures in her vertebra and later undergoing surgery that would input two permanent titanium rods to support her spine. Fighting all odds, she made a strong recovery and in 2015 was appointed the Team Coach to the Mexican Eventing Team. O’Connor now spends her time teaching students, commentating at international events, and inspiring others through motivational speaking.