Ruy Tadeu Aquino de Oliveira (born February 1, 1953) is a former international freestyle swimmer from Brazil, who competed at one Summer Olympics for his native country.He was at the 1971 Pan American Games, in Cali, where he won two bronze medals, in the 4×100-metre freestyle and in the 4×200-metre freestyle, both breaking the South American record.
He also finished 7th in the 100-metre freestyle.At the 1972 Summer Olympics, in Munich, he finished 4th in the 4×100-metre freestyle (6 seconds and a half below the South American record).
He also swam the 100-metre freestyle, 200-metre freestyle and 4×200-metre freestyle, not reaching the finals.