Helicops is a genus of Neotropical watersnakes containing 16 species. Based on morphological (scale counts, dentition, coloration, and hemipenis anatomy) and genetic data (16S rRNA and C-mos genes), we identify a new species of this genus. The new taxon is diagnosed by having 17-17-15 dorsal scale rows; 111–117 ventral plates; 41–56 subcaudals without keels; nasal entire; 18–21 2 maxillary teeth; hemipenis bilobed, semicalyculate, and semicapitate; dorsum uniformly medium brown or dark brown; venter cream or light brown with two medial rows of black markings, usually semilunar in shape. The new species occurs from southeastern to northern Minas Gerais state, Brazil.