Geraestus or Geraistos () may refer to:
Mythical figures: Geraestus, a son of Zeus and brother of Taenarus Geraestus, a Cyclops on whose grave in Attica Hyacinthus of Lacedaemon had his daughters sacrificed
Geographical names: Geraistos, the southernmost cape of Euboea, now Cape Mandelo Geraestus (Euboea), an ancient port in Euboea