Sérgio Geraldo de Alencar Rodrigues (born February 14, 1930) is a former international freestyle swimmer and water polo player from Brazil.At the 1948 Summer Olympics in London, he finished 8th in the 4×200-metre freestyle final, and swam the 100-metre freestyle, not reaching the finals.At the 1952 Summer Olympics in Helsinki, he participated in the water polo, finishing 13th.