Official Olympic records consider Oscar Swahn of Sweden the oldest to win an Olympic Gold Medal. He achieved that feat in sport shooting at the 1912 Summer Olympics, at the age of 64 years 257 days. He is also accepted as the oldest participant in any regular Olympic Games ( Summer or Winter ), at the age of 72 years 279 days, in the 1920 Summer Olympics. At those Games he received a Silver Medal as a team member. In doing so, he is credited with being the oldest person to win an Olympic Medal of any colour, a record that still stands to this day. See: here and here .
The oldest person to ever participate in any modern International Olympic Games ( Summer, Winter or Paralympic ) is a 75-year old Japanese curler at the 2010 Vancouver Winter Paralympic Games.
OTHER AGE-RELATED OLYMPIC RECORDS
Willie & Laurence Jackson, Robin Welsh &Tom Murray of Britain's
curling team at the 1924 International Winter Olympics.
The oldest person to win an Olympic Gold Medal at a Winter Olympics is Robin Welsh of Britain in 1924, at 54 years 100 days in curling. The oldest person ever to compete in a Winter Olympics is Sweden's 1924 Silver Medalist, Karl August Kronlund, at 58 years 155 days, also achieved in team curling. See: here .
MEDAL WINNERS AT BOTH SUMMER & WINTER OLYMPICS
While not a senior, the only person to win a gold medal in both the Winter and Summer Olympic Games is Eddie Eagan (United States), in individual boxing (1920), and, the bobsled team (1932). See: here