Achelois was a name attributed to several figures in Greek mythology.*Achelois (Greek: Ἀχελωίς, English translation: "she who washes away pain") was a minor Greek moon goddess. She was frequently the recipient of sacrifices ordered by the Dodonian Oracle, in order for her subjects to be cured of their ailments.
- Achelois was a surname of the Sirens, the daughters of Achelous.
- Achelois was a general name for water-nymphs, as in Columella, where the companions of the Pegasids are called Acheloides.