Seleucus III Ceraunus or Soter (c. 243 BC - 223 BC), eldest son of Seleucus II Callinicus, was a Seleucid king, who after a brief reign of three years (225 BC-223 BC) was assassinated in Asia Minor by members of his army while on campaign against Attalus I of Pergamon. His title "Ceraunus" means "Thunder" in Greek.