Oa, also Oae or Oai, (Greek, Ancient (to 1453);: Ὄα or Ὀά) was a deme of ancient Attica, originally of the phyle of Pandionis, but after 127/8 AD, of the phyle of Hadrianis, sending four delegates to the Athenian Boule.[1]
Its site is located near modern Papangelaki.