Arethusa means "the waterer".
- In Greek mythology, Arethusa was one of the Hesperides
- A nymph, daughter of Nereus (making her a Nereid), Arethusa ran from a suitor, Alpheus, the river god, making her way to Sicily. Artemis changed her into a fountain. Alpheus swam underground and mingled his waters with hers.
- Arethusa is a fountain near Syracuse, Sicily.