Piau is a municipality in Minas Gerais, Brazil.
Piau may also refer to:
Piau River, a river in Bahia, Brazil Piau (footballer), Eronildes de Souza (born 1948), Brazilian football winger Sandrine Piau (born 1965), French soprano
See also Piau-Engaly, a winter sports resort in the French Pyrenees Piaus River, a river in Tocantins, Brazil