In 2004, Mark Barr competed in his first Paralympic Games, earning two fourth-place finishes in the 100m butterfly and the 400m free. Finishing one spot short of a medal has served as a motivator for Barr, particularly in the 100m fly. After setting a new American record in the event late in 2005, he set a new Pan American record at the 2006 U.S. Paralympics Swimming National Championships and again later that year at the IPC Swimming World Championships, where he won a silver medal in the event.
Barr lost his leg to a tumor when he was 14 years old. He had been swimming competitively since he was four years old and, up until his amputation, also played baseball and soccer. While going through chemotherapy, Barr was introduced to Paralympic swimming as a way of cheering him up and he has gone on to become a strong member of the U.S. Paralympics Swimming National Team.
In June 2008, while preparing for Beijing, Barr had his appendix removed. Despite the setback, Barr continued to train and headed to Beijing to compete in six events, including the 100m butterfly S9.
Barr is a student at California Polytechnic University and a member of the swim team, in addition to being a volunteer assistant swim coach for age group swimmers in the evenings. In his spare time, he enjoys jamming on the guitar and playing golf and football. His two older brothers share his love for swimming and also play soccer.
- 2008: U.S. Paralympic Team member, Swimming - Paralympic Games, Beijing, China
- 2006: Silver medal, 100m butterfly (Pan American record); Bronze medal, 4x100m medley relay - International Paralympic Committee (IPC) Swimming World Championships, Durban, South Africa
- 2006: American and Pan American record, 100m butterfly - U.S. Paralympics Swimming National Championships, San Antonio, Texas
- 2004: Fourth place, 100m butterfly, 400m freestyle - Paralympic Games, Athens, Greece
- 2003: Two American records, 4x50m relay 34 pt., 4x100m relay 34 pt. - Canadian Nationals, Edmonton, Canada