(Μουσαῖος), an officer of Antiochus the Great, king of Syria. After the decisive battle of Sipylus, B. C. 190, he came as an ambassador to the Scipios, then at Sardis, to request permission for the king to send commissioners to treat of peace. (Plb. 21.13; Liv. 37.45; App. Syr. 38.) In B. C. 188 Musaeus was again sent by Antiochus to Cn. Manlius Vulso, the Roman proconsul in Asia, to learn the terms on which the peace between his master and the Romans would be finally ratified. (Plb. 22.24; Liv. 38.37; App. Syr. 39.)