João Derly de Oliveira Nunes Jr. (born June 2, 1981 in Porto Alegre, Rio Grande do Sul) is a former male judoka from Brazil, and one of only two Brazilians to ever become a two-time world champion (along with Mayra Aguiar), winning consecutively the 2005 World Judo Championships and 2007 World Judo Championships. He also won the junior world championship in 2000, the 2007 Pan American Games, and has 5 gold, 2 silver and 1 bronze medals in Judo World Cups.
After the 2002 South American Games he tested positive for banner diuretic drugs he used in order to maintain his weight class.
After retirement as a judoka, he was elected as city council member and later as a member of the House of Representatives. Later he was nominated secretary of sports of the State of Rio Grande do Sul.