Philoxenus of Eretria (Greek: Φιλόξενος ὁ Ἐρετριεύς) was a painter from Eretria. He was the student of Nicomachus of Thebes. Philoxenus copied his speed in painting. He found new and fast ways of painting. Pliny said a picture Philoxenus painted was the best painting. It was of a battle of Alexander the Great with Darius. He painted it for King Cassander. The same subject was used in the Alexander Mosaic in the House of the Faun, in Pompeii.