Greek painter of unknown date. According to Pliny (XXXV.16), it was either Kleanthes or the otherwise unknown Philokles of Egypt who invented outline drawing. Athenagoras (xvii) gave credit to the otherwise unknown Saurios of Samos for the invention of this technique, but included Kleanthes in his list of the earliest artists (those who worked before the gods were depicted), incorrectly assuming that secular subjects were depicted before divine ones. Indeed, deities were shown in at least two of the three paintings by Kleanthes held in the Temple of Artemis Alpheiosa in the territory around Olympia (Strabo: VIII.343; Athenaeus: VIII.346b–c): the Birth of Athena and Poseidon Offering a Tunny Fish to Zeus (Zeus was in labour, perhaps with the second birth of Dionysos). The third painting was the Fall of Troy. No other painting by Kleanthes is recorded, and none of his work survives.