Astynous or Astynoos (Ancient Greek: Ἀστύνοος) is a name that may refer to one of the following characters in Greek mythology:
Astynous, son of Phaethon, son of Eos. He was the father of King Sandocus of Celendreis who in turn fathered King Cinyras of Cyprus.
Astynous, a defender of Troy killed by Diomedes.
Astynous, son of Protiaon and another defender of Troy. Polydamas entrusted to him his horses before going into the battle. Astynous was killed by Neoptolemus during the Trojan War.