George L. Eyser was born on August 31, 1871 in Kiel, Germany. When he was 14, his family immigrated to the United States. They moved to St. Louis, Missouri where Eyser worked as a bookkeeper at a construction factory. There, he joined a local gymnastics club Concordia Turnverein Saint Louis. In 1894 Eyser obtained US citizenship. He lost most of his left leg, which had to be amputated after a train ran over it. It was replaced by a wooden prosthesis which allowed physical activities such as running and jumping. A keen sportsman, Eyser pursued training for the 1904 Olympics. There were two sets of gymnastic events: International Turners Championship and Olympic Gymnastics Championships.
Eyser competed in both sets and did poorly in the first one. He was the 71st in another gymnastic all-around event. He also competed in the athletics triathlon, but finished the last. He performed much better in the second competition set. He won six medals in total, of which three were gold, two silver, and one bronze.
Prior to 2008, Eyser was the only person with an artificial leg to have competed at the Olympic Games.