Chiaki Ishii

is a Japanese Brazilian judoka, who won Brazil's first Olympic medal in judo at the 1972 Summer Olympics in Munich, West Germany.

Career Ishii trained judo since a very young age, at a dojo located near his house, and graduated in pedagogy at Waseda University. He was eager to participate in the first judo Olympic tournament at the 1964 Summer Olympics in Tokyo, but lost his spot to eventual gold medalist Isao Okano. Frustrated, he quit the sport and decided to emigrate to Brazil, where he would become a farmer. After a sixty-day boat trip, Ishii arrived in Brazil and worked in a farm at a Japanese Brazilian community in Presidente Prudente. After being convinced to fight a local judo tournament for fun, Ishii's skills impressed enough for the inhabitants to ask him to become a judo teacher. Added to Ishii's frustration with the farming life, he started to teach the martial art, eventually opening a dojo in São Paulo. In 1969, Ishii was naturalized Brazilian to take part in judo competitions.

He won a bronze medal at both the 1972 Summer Olympics in Munich, and the 1971 World Judo Championships.

Two of Ishii's three daughters, Tânia and Vânia Ishii, are also judokas. Vânia was a gold medalist at the Pan-American Games and both Vânia and Tânia represented Brazil in the Olympics.

Ishii is considered the founding father of modern Brazilian Judo and his legacy is directly linked to the prowess of judo being the only sport in which Brazil has collected medals in every Olympic Games since Los Angeles 1984.