In Greek mythology, Hecaterus or Hekateros (Ἑκάτερος) was a minor god and the father of five daughters (the Hecaterides) by the daughter of Phoroneus, and through them grandfather of the Oreads, Satyrs, and Curetes.
As rivers are generally fertile, Inachus had many children, the chief of whom were his two sons, Phoroneus and Aegialeus or Phegeus, and his two daughters, Io and Philodice, wife of Leucippus.