(Ἀγαθοκλῆς), a Greek historian, who wrote the history of Cyzicus (περὶ Κυζίκου). He is called by Athenaeus both a Babylonian (i. p. 30a. ix. p. 375a) and a Cyzican. (xiv. p. 649f.) He may originally have come from Babylon, and have settled at Cyzicus. The time at which Agathocles lived is unknown, and his work is now lost.