Seleucus III Keraunos ("thunderbolt"): name of a Seleucid king, ruled from 225 to 222.
Successor of: Seleucus II Callinicus
- Born in 243; his real name is Alexander
- December 225: Succeeds his father
- Tries to recover those parts of Asia Minor that were lost by his father Seleucus II Callinicus and his uncle Antiochus Hierax to king Attalus I Soter of Pergamon; mixed successes.
- April-June 222: poisoned by a court conspiracy in the second year of his reign
- Succeeded by his brother Antiochus III the Great