In Greek mythology, the name Echion (Ancient Greek: Ἐχίων (gen.: Ἐχίονος), derivative of ἔχις echis "viper") referred to five different beings:
- Echion, one of the Gigantes, known for great strength (though not necessarily great size) and having an ability to change the course or direction of winds.
- Echion, one of the surviving Spartoi, the "sown men" that sprang up from the dragon's teeth sown by Cadmus, and principally known for skill in battle and bravery; "it was Echion who, for his great valor, was preferred by Cadmus to be his son-in-law": Echion was father of Pentheus and Epeiros by Agave.
- Echion, one of the Argonauts, son of Hermes and Antianeira or Laothoe (daughter of Menetus), brother of Erytus; participated in the Calydonian Boar Hunt, according to Hyginus and Ovid.
- Echion, one of the suitors who came from Dulichium to compete for Penelope.
- Echion, one of the Greeks who fought at the Trojan War. Son of Portheus, he was one of the men hidden in the Trojan horse and was killed. The doomed Greek is a "tough but battle weary warrior, plagued by phantasms of his death".