Nelson Luiz Bittencourt Sardenberg (born August 1, 1970 in Belo Horizonte) is a Brazilian karate fighter.
In 1999, Nelson was defeated on the final of the 1999 Pan American Games in Winnipeg by the American John Fonseca.
In 2002, fighting for the Pan-American Championship, Nelson had his jaw broken and required a surgical intervention.
In 2003, Nelson was defeated by the American John Fonseca on the final of the 2003 Pan American Games in Santo Domingo.