Akademos or Academus (/ˌækəˈdiːməs/; Ancient Greek: Ἀκάδημος; also Hekademos or Hecademus (Ἑκάδημος)) was an Attic hero in Greek mythology.

Plutarch in his biography of the Athenian king Theseus (the slayer of the Minotaur) says that, after being widowed and reaching age 50, the king abducted the beautiful 12-year-old Helen (long before she married Menealaus, met Paris and was the cause of the Trojan War). Due to this outrage, her twin brothers Castor and Pollux invaded Attica to liberate their sister and threatened to destroy Athens. Akademos spared the city by telling them where she was (hidden at Aphidnae). For this Akademos was venerated by the city as a savior. Also for this reason the Tyndarids always showed him much gratitude, and whenever the Lacedaemonians invaded Attica, they always spared the land belonging to Academus which lay on the Cephissus, six stadia from Athens.