Who was the youngest Olympian gold medal ever and also the youngest who ever win a medal and who ever compete in the Olympics?

The youngest athlete to participate at the Modern Olympics was DimitriOS Loundras of Greece who was 10 years, 216 days old when he competed in men's team parallel bars gymnastics at the 1896 Games in Athens.

The youngest athlete to win a gold medal is Marjorie Gestring of the United States who was 13 years, 267 days old when she won the women's springboard diving event at the 1936 Summer Games in Berlin.