Dayus may refer to: Dayus (leafhopper), a genus of insects in the family Cicadellidae Dayus, a genus of polychaete worms in the family Histriobdellidae; synonym of Steineridrilus Dayus, a genus of crustaceans in the family Gynodiastylidae; synonym of Jennidayus Kathleen Dayus (1903–2003), an English author

See also Dayu (disambiguation)