| Pacorus I 𐭐𐭊𐭅𐭓 | |
|---|---|
 Coin of Pacorus I, Ecbatana mint | |
| King of the Parthian Empire | |
| Reign | c. 39 BC |
| Predecessor | Orodes II |
| Successor | Orodes II |
| Died | 38 BC Cyrrhestica |
| Spouses | Sister of Artavasdes II |
| Dynasty | Arsacid dynasty |
| Father | Orodes II |
| Religion | Zoroastrianism |
Pacorus I (also spelled Pakoros I; Parthian: 𐭐𐭊𐭅𐭓; died 38 BC) was a Parthian prince, who was the son and heir of Orodes II (r. 57–37 BC). The numismatist David Sellwood deduced that Pacorus ruled in c. 39 BC. It is uncertain whether Pacorus ruled alongside his father, or ruled independently. His wife was an unnamed Armenian princess, who was a sister of the Artaxiad king of Armenia, Artavasdes II (r. 55–34 BC).
Following the Parthian victory against the Romans at the Battle of Carrhae in 53 BC, the Parthians attempted to capture Roman-held territories in Western Asia, with Pacorus acting as one of the leading commanders. Although they were initially successful, they were repelled by the Romans. Pacorus himself was defeated and killed at the Battle of Mount Gindarus by the forces of the Publius Ventidius Bassus. His death spurred a succession crisis in which Orodes II, deeply afflicted by the death of his favourite son, relinquished the throne to his other son Phraates IV (r. 37–2 BC) as his new heir.