Themisto may refer to:

Greek mythology Themisto, the third and last wife of Athamas Themisto (mythology), various figures including: Themisto, a daughter of the river god Inachus, who became the mother of Arcas by Zeus Themisto, one of the Nereids Themisto, daughter of the Hyperborean king Zabius, mother of Galeos by Apollo

Other meanings Themisto (moon) of Jupiter Themisto (crustacean), a genus of amphipod crustaceans

See also Themistocles (disambiguation)