In Greek mythology, Hippo (Ancient Greek: Ἱππώ or Ἵππωτος Hippô means 'horse'^[1] or 'like a swift current'^[2]) may refer to the following personages:

• Hippo, one of the 3,000 Oceanids, water-nymph daughters of the Titans Oceanus and his sister-spouse Tethys.^[2][3]
• Hippo, a Thespian princess as one of the 50 daughters of King Thespius and Megamede^[4] or by one of his many wives.^[5] When Heracles hunted and ultimately slayed the Cithaeronian lion,^[6] Hippo with her other sisters, except for one,^[7] all laid with the hero in a night,^[8] a week^[9] or for 50 days^[10] as what their father strongly desired it to be.^[11] Hippo bore Heracles a son, Capylus.^[12]