Who is the youngest Olympian and the youngest Olympic gold medallist in history?

Dimitrios Loundras is the youngest athlete in modern Olympic history. He won bronze at 10 years old at 1896 Athens Olympics as part of Greek gymnastics team. Meanwhile, ex-South Korean speed skater Kim Yun-mi is the youngest athlete to win Olympic gold. She was 13 years and 86 days old when she bagged gold in 3,000-metre relay at 1994 Olympics.