Athos Procópio de Oliveira Júnior (born January 3, 1943 in Catanduva) is a former international freestyle and backstroke swimmer from Brazil.
At the 1959 Pan American Games in Chicago, he finished 7th in the 100 metre backstroke. He also swam the 4 × 100-metre medley.
At the 1960 Summer Olympics, in Rome, he swam the 100-metre backstroke and the 4×100-metre medley, not reaching the finals.
At the 1963 Pan American Games, in São Paulo, he won two bronze medals in the 100-metre backstroke, and in the 4×200-metre freestyle.
At the 1964 Summer Olympics, in Tokyo, he swam the 100-metre freestyle and the 4×100-metre medley, not reaching the finals.
Among other achievements, he was part of the Brazilian team champion of the 4×100-metre freestyle relay in the 1964 South American Absolute Championship, in Guayaquil, Ecuador. Team composed of Alvaro Pires, Athos Procópio de Oliveira, Paulo Salles Cunha, and Antonio Celso Guimarães.