In Greek mythology, Andreus (; Ancient Greek: Ἀνδρεύς) may refer to two distinct individuals:
- Andreus, son of the river-god Peneus in Thessaly, from whom the district about Orchomenos in Boeotia was called Andreis.[1] With Evippe, daughter of Leucon, Andreus had a son Eteocles, his successor.[2]
- Andreus, in another passage Pausanias speaks of Andreus (it is, however, uncertain whether he means the same man as the former) as the person who first colonized the island of Andros.[3] According to Diodorus Siculus, Andreus was one of the generals of Rhadamanthys, from whom he received the island afterwards called Andros as a present.[4] Stephanus of Byzantium,[5] Conon[6] and Ovid[7] call this first colonizer "Andrus" (son of Anius) and not Andreus.[8]