For other uses of the word Dati, see Dati (disambiguation).
Datis or Datus was a Median admiral who served the Persian Empire, under Darius the Great. He is most notable for his joint leadership with Artaphernes of the Persian forces in the first campaign of the Persian Wars against the Greeks.
Datis was one of the Persian commanders responsible for the siege of Naxos and the sacking of Eretria in 490 BC along with the infamous Persian Immortals. He was also leader of the Persian assault force on the Athenians at the Battle of Marathon in the same year. Ctesias of Cnidus relates that Datis was slain at Marathon and that the Athenians refused to hand over his body, however this conflicts with Herodotus' earlier analysis that Datis survived the battle
Datis was originally called to duty alongside Artaphernes for the Greek invasion because Darius I had decided to temporarily relieve Mardonius of military service due to an injury he suffered in the Thracian campaign. Datis is mocked in Aristophanes' play "Peace", where Trygaeus exclaims: Now is the time to sing as Datis did, as he masturbated at high noon, "Oh pleasure! oh enjoyment! oh delights!"