The only athlete to win medals in both summer and winter Olympics at a single Olympics is Eddie Eagan. Eagan won a gold medal in boxing at the 1920 Antwerp Olympics and then went on to win another gold medal in the bobsleigh event at the 1932 Lake Placid Olympics. His unique achievement makes him an exceptional figure in Olympic history, showcasing his versatility across vastly different sports. Eagan remains a symbol of athleticism and dedication.