The common snook is a species of marine fish in the family Centropomidae of the order Perciformes. The common snook is also known as the sergeant fish or robalo. It was originally assigned to the sciaenid genus Sciaena; Sciaena undecimradiatus and Centropomus undecimradiatus are obsolete synonyms for the species.

Centropomus is a genus of predominantly marine fish comprising the family Centropomidae. The type species is Centropomus undecimalis, the common snook. Commonly known as snooks or róbalos, the Centropomus species are native to tropical and subtropical waters of the western Atlantic and eastern Pacific Oceans.