From Wikipedia:

* Freddy Adu: IMG Soccer Academy at age 12 and turned professional at 14.[106]
* Cho Hunhyun: A professional go player at age 9.[107]
* Fu Mingxia: A diver, referred to as a child prodigy by at least two sources,[108][109] and was an Olympic gold medalist at 13.
* Willie Mosconi: Nicknamed "Mr. Pocket Billiards" he played professionals at age 6.[110]
* Ronnie O'Sullivan: snooker player. Scored his first century break aged 10,[111] his first maximum at 15 and was youngest ever winner of a ranking event at 17.
* Michelle Wie: Qualified for the USGA Women's Amateur Public Links at 10 and won the same event at 13, making her the youngest person both to qualify for and win a USGA adult national championship.[112]
* Tiger Woods: He first won the Optimist International Junior tournament at age 8, playing in the 9-10 age group since there was no group for 8-year-olds at the time.[113][114]
* Wayne Gretzky: At age 6 he was skating with 10-year-olds. By the age of ten he scored 378 goals and 139 assists in just 85 games with the Nadrofsky Steelers. [115]
* Dominique Moceanu: Gymnast. Reached the elite level of the sport at age 9 and was performing beyond-Olympic level skills even earlier. Won the Senior US National Championships at age 13, the youngest to ever do so, and will forever hold that record, as the age limit for senior competitors has now been raised. Won an Olympic gold medal at age 14 with team.
* Victor De Leon III: The Youngest Professional Gamer in the World started his gaming at age 2. Started his competitions at age 4 and went Professional at age 6. He doesn't compete with gamers his age. He competes with gamers twice or triple his age.[116]
* Wilfred Benitez: Boxer WBA Benitez is the youngest world champion in boxing history, capturing the WBA junior welterweight title, at the age of 17 years and 5 months, with a split decision over Antonio Cervantes.[117]
* Christian Friedrich Heinecken: The book The Life, Deeds, Travels and Death of the Child of Lubeck was based on his life and he was an influence on The Hampdenshire Wonder. He allegedly "knew by heart the principal incidents in the Pentateuch" by age 1.[118]
* Okita Sōji (1842 or 1844-1868): Prodigy of kenjutsu (swordsmanship), who defeated a kenjutsu master by age 12 and became a master of kenjutsu and a school head (Jukutou) at 18 or so. He died from tuberculosis in his mid-twenties.
* Cathy Forbes: The Polgar Sisters: Training or Genius?. Henry Holt & Co. ISBN 0805024263.
* Dempsey Andrews : Ice Skater - Youngest in the World to perform on ice with the World Famous Russian Ice Stars, won her 1st GOLD podium position age 6 now age 11 and the winner of 15 GOLD, 2 silver 2 bronze medals across the UK, youngest in Northern Ireland at this high level. www.freewebs.com/champsonice

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